BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Masanobu Kaneko (Kyushu University) DTSTART:20201013T080000Z DTEND:20201013T083000Z DTSTAMP:20260422T214834Z UID:JENTE/1 DESCRIPTION:Title: A new approach to Kawashima's relation for multiple zeta values\nby Masa nobu Kaneko (Kyushu University) as part of Japan Europe Number Theory Exch ange Seminar\n\n\nAbstract\nKawashima's relation is conjecturally one of t he largest classes of relations among multiple zeta values. In his highly original work\, Gaku Kawashima introduced and studied a certain Newton ser ies\, which we call the Kawashima function\, and deduced his relation by e stablishing several properties of this function.\nIn this talk\, we will d escribe a new approach to the Kawashima function without using Newton seri es. We first establish a generalization of the theory of regularizations o f divergent multiple zeta values for a Hurwitz type multiple zeta values\, and then relate it to the Kawashima function. Via this connection\, we ca n prove a key property of the Kawashima function to establish Kawashima's relation.\nThis is a joint work with Ce Xu and Shuji Yamamoto\n LOCATION:https://researchseminars.org/talk/JENTE/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Wadim Zudilin (Radboud University Nijmegen) DTSTART:20201013T083000Z DTEND:20201013T090000Z DTSTAMP:20260422T214834Z UID:JENTE/2 DESCRIPTION:Title: (Q uasi-)magnetic modular forms\nby Wadim Zudilin (Radboud University Nij megen) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstrac t\nGiven a positive even integer $k$\, let $E_k(\\tau)$ stands for the nor malised Eisenstein series of weight $k$\; denote $$\\Delta(\\tau)=q\\prod_ {m=1}^\\infty(1-q^m)^{24}=(E_4^3-E_6^2)/1728$$ with $q=e^{2\\pi i\\tau}$\, and $\\delta=\\frac{1}{2\\pi i}\\frac{d}{\\d\\tau}=q\\frac{d}{dq}$. About ten years ago Honda and Kaneko observed surprising arithmetic properties of the meromorphic modular function $\\Delta^{5/6}/E_4^2$ of weight 2\, wh ile the recent work of Li and Neururer (inspired by an observation of Broa dhurst and this speaker) brought to life an even stronger arithmetic for t he modular function $\\Delta/E_4^2$ of weight 4. To convince the attendee about it\, you are invited to verify that the anti-derivatives $\\delta^{- 1}(\\Delta/E_4^2)$ and $\\delta^{-1}(E_4\\Delta/E_6^2)$ have integer coeff icients in their $q$-expansions. At the same time\, these series are trans cendental over the field of quasi-modular functions. I will discuss this p henomenon (in a greater generality!) and ideas behind its proof in my talk . The talk is based on my joint work with Vicenţiu Paşol.\n LOCATION:https://researchseminars.org/talk/JENTE/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Nils Matthes (University of Oxford) DTSTART:20201020T080000Z DTEND:20201020T083000Z DTSTAMP:20260422T214834Z UID:JENTE/3 DESCRIPTION:Title: Al gebraic independence results for iterated integrals of meromorphic modular forms\nby Nils Matthes (University of Oxford) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nAs a byproduct of their rec ent work on the magnetism phenomenon for modular forms\, Pasol and Zudilin proved that primitives of the meromorphic modular forms Delta/E_4^2\, E_4 *Delta/E_6^2\, and E_6*Delta/E_4^3 are algebraically independent over the differential field generated by quasimodular forms. We will report on work in progress on how to generalize this to iterated integrals of arbitrary meromorphic modular forms.\n LOCATION:https://researchseminars.org/talk/JENTE/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Nobuo Sato (National Taiwan University) DTSTART:20201020T084000Z DTEND:20201020T091000Z DTSTAMP:20260422T214834Z UID:JENTE/4 DESCRIPTION:Title: Fr om the 2-1 formula for multiple zeta values to iterated beta integrals \nby Nobuo Sato (National Taiwan University) as part of Japan Europe Numbe r Theory Exchange Seminar\n\n\nAbstract\nA multiple zeta value\, or MZV in short\, is a generalization of the Riemann zeta value at a positive integ er\, defined by a certain nested infinite sum. It is well known that MZV's satisfy a large family of linear/algebraic relations over the rationals. Among such relations is the so-called two-one formula\, which was first co njectured by Ohno and Zudilin as a generalization of their formula and was later proved by Zhao in a quite ingenious but also mysterious way. In my talk\, I would like to revisit the two-one formula from the viewpoint of i terated beta integrals introduced by Hirose and myself. Our new viewpoint provides a clear understanding of the phenomena as well as a universal way to prove identities of similar flavors\, such as Zagier’s 2-3-2 formula and its generalization.\n LOCATION:https://researchseminars.org/talk/JENTE/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Yuta Suzuki (Nagoya University) DTSTART:20201027T080000Z DTEND:20201027T083000Z DTSTAMP:20260422T214834Z UID:JENTE/5 DESCRIPTION:Title: On the irrationality of sums of reciprocals of Fibonacci numbers restricted to prime-like indices\nby Yuta Suzuki (Nagoya University) as part of J apan Europe Number Theory Exchange Seminar\n\n\nAbstract\nIn 1989\, André -Jeannin proved the irrationality of the sum of reciprocals of Fibonacci n umbers. A possible further question is to ask which subsums of reciprocal of Fibonacci numbers are still irrational. In this talk\, we prove the irr ationality of such subsums with indices restricted to thin "prime-like" nu mbers. For example\, we can show the irrationality of the sum of reciproca ls of Fibonacci numbers of the prime-square indices. Our proof is an exten sion of Erdős's partial result (1968) towards the irrationality of $\\sum _{p}\\frac{1}{2^p-1}$. (joint work with D. Duverney and Y. Tachiya)\n LOCATION:https://researchseminars.org/talk/JENTE/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Jori Merikoski (University of Turku) DTSTART:20201027T084000Z DTEND:20201027T091000Z DTSTAMP:20260422T214834Z UID:JENTE/6 DESCRIPTION:Title: A cubic analogue of the Friedlander-Iwaniec spin along primes\nby Jori M erikoski (University of Turku) as part of Japan Europe Number Theory Excha nge Seminar\n\n\nAbstract\nIn 1998 Friedlander and Iwaniec famously proved that there are infinitely many primes of the form a^2+b^4. To show this t hey defined the spin of Gaussian integers by using the Jacobi symbol\, and one of the key ingredients in the proof was to show that the spin becomes equidistributed along Gaussian primes. To generalize this\, by using the cubic residue character on the Eisenstein integers\, we define the cubic s pin of ideals of the twelfth cyclotomic extension. We prove that the cubic spin is equidistributed along prime ideals. The proof of this follows clo sely along the lines of Friedlander and Iwaniec. We also explain how this cubic spin is related to primes of the form a^2+b^6 on the Eisenstein inte gers.​\n LOCATION:https://researchseminars.org/talk/JENTE/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Jan-Willem van Ittersum (Utrecht University) DTSTART:20201103T080000Z DTEND:20201103T083000Z DTSTAMP:20260422T214834Z UID:JENTE/7 DESCRIPTION:Title: A Kaneko-Zagier equation for Jacobi forms\nby Jan-Willem van Ittersum (U trecht University) as part of Japan Europe Number Theory Exchange Seminar\ n\n\nAbstract\nThe Kaneko-Zagier equation is a second order differential e quation depending on a parameter k which gives rise to an infinite family of modular forms as solutions. These solutions are closely related to Weie rstrass p function\, which becomes clear by considering the inverse (under composition) of a suitably normalized generating series of the solutions for integer values of k. In this talk\, we study an analogue of the Kaneko -Zagier differential equation for Jacobi forms. We point to three features of the infinite family of solutions. First of all\, the solutions are qua si-Jacobi forms\, and we determine their transformation under the Jacobi g roup. Secondly\, the inverse of a suitable normalized generating series of these solutions is again a well-known function\, namely a ratio of theta functions. Finally\, a special feature of the solutions is the polynomial dependence of the index parameter. (Joint with Georg Oberdieck and Aaron P ixton)\n LOCATION:https://researchseminars.org/talk/JENTE/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Kunihiro Ito (NEC Corporation/Tohoku University) DTSTART:20201103T084000Z DTEND:20201103T091000Z DTSTAMP:20260422T214834Z UID:JENTE/8 DESCRIPTION:Title: On a multi-variable Arakawa-Kaneko zeta function for non-positive or positiv e indices\nby Kunihiro Ito (NEC Corporation/Tohoku University) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nThe Arakawa -Kaneko zeta function (the xi function) and Kaneko-Tsumura zeta function ( the eta function) are defined as the Mellin transformation of the generati ng function of multi-poly-Bernoulli numbers and notably related to multi-p oly-Bernoulli numbers and multiple zeta values. One striking discovery is the duality of the multi-variable eta function. Specifically\, one can obt ain the duality formula among multi-indexed poly-Bernoulli numbers of B-ty pe and\, using the formula for special values of the multi-variable eta fu nction in terms of a linear combination of multiple zeta values\, a new fa mily of relations among multiple zeta values.\nIn this talk\, we introduce our study on the multi-variable xi function. First\, its analytic continu ation to an entire function. Second\, a duality formula among multi-indexe d poly-Bernoulli numbers of C-type which is regarded as a special case of the possible duality of the multi-variable xi function. Third\, an explici t procedure for writing the special values of the multi-variable xi functi on as a linear combination of multiple zeta values.\n LOCATION:https://researchseminars.org/talk/JENTE/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Markus Schwagenscheidt (ETH Zürich) DTSTART:20201110T080000Z DTEND:20201110T083000Z DTSTAMP:20260422T214834Z UID:JENTE/9 DESCRIPTION:Title: Ar ithmetic properties of meromorphic modular forms\nby Markus Schwagensc heidt (ETH Zürich) as part of Japan Europe Number Theory Exchange Seminar \n\n\nAbstract\nWhile investigating the Doi-Naganuma lift\, Zagier studied certain cusp forms f_{k\,d} of weight 2k associated to positive discrimin ants d. These cusp forms also appear prominently in the kernel function fo r the Shimura-Shintani correspondence. Moreover\, Kohnen and Zagier showed that they have rational periods and geodesic cycle integrals. The natural generalization of the function f_{k\,d} to negative discriminants d yield s a meromorphic modular form with poles at the CM points of discriminant d . Together with C. Alfes-Neumann\, K. Bringmann\, S. Löbrich\, and J. Mal es\, we showed that these meromorphic modular forms have interesting arith metic properties\, too. Indeed\, they have rational periods and cycle inte grals\, and integral Fourier coefficients which satisfy strong divisibilit y conditions. Moreover\, their Fourier coefficients are non-vanishing and have very regular sign changes. If time permits\, we will also discuss a s urprising relation with the coefficients of the modular j-invariant and th e partition function.\n LOCATION:https://researchseminars.org/talk/JENTE/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Toshiki Matsusaka (Nagoya University) DTSTART:20201110T084000Z DTEND:20201110T091000Z DTSTAMP:20260422T214834Z UID:JENTE/10 DESCRIPTION:Title: L inking numbers and modular forms for the triangle groups\nby Toshiki M atsusaka (Nagoya University) as part of Japan Europe Number Theory Exchang e Seminar\n\n\nAbstract\nThe coset space SL(2\,Z)\\SL(2\,R) is diffeomorph ic to the complement of the trefoil knot in the 3-sphere. For each hyperbo lic matrix in SL(2\,Z) or real quadratic irrationality\, we can naturally construct a simple closed orbit in this space\, which is called a modular knot. At ICM 2006\, Ghys showed a beautiful relation that the linking numb er of the modular knot and the missing trefoil is equal to the Rademacher invariant. This invariant classically appears in the transformation law of the Dedekind eta function\, and has the expression as a geodesic cycle in tegral of the Eisenstein series of weight 2. In this talk\, we generalize Ghys’ result to the knot complement of the torus knots. To get a similar relation between linking numbers and cycle integrals\, modular forms for triangle groups have crucial roles. This is joint work with Jun Ueki (Toky o Denki University).\n LOCATION:https://researchseminars.org/talk/JENTE/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Shin-ichiro Seki (Tohoku University) DTSTART:20201117T080000Z DTEND:20201117T083000Z DTSTAMP:20260422T214834Z UID:JENTE/11 DESCRIPTION:Title: M ultivariable connected sums and transport relations\nby Shin-ichiro Se ki (Tohoku University) as part of Japan Europe Number Theory Exchange Semi nar\n\n\nAbstract\nIn 2019\, the speaker and Shuji Yamamoto (Keio Universi ty) gave a new proof of the duality for multiple zeta values by series man ipulation. The key ingredients were the connected sum and its transport re lations. In this talk\, we introduce the multivariable connected sum which generalizes Seki-Yamamoto's one\, and show new transport relations. As an application\, we obtain a class of functional relations among multiple po lylogarithms which contains Ohno's relations. This is joint work with Hana michi Kawamura (Seifu Senior High School) and Takumi Maesaka (Kanazawa Uni versity Senior High School).\n LOCATION:https://researchseminars.org/talk/JENTE/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Annika Burmester (Universität Hamburg) DTSTART:20201117T084000Z DTEND:20201117T091000Z DTSTAMP:20260422T214834Z UID:JENTE/12 DESCRIPTION:Title: C ombinatorial multiple Eisenstein series\nby Annika Burmester (Universi tät Hamburg) as part of Japan Europe Number Theory Exchange Seminar\n\n\n Abstract\nMultiple q-zeta values are formal q-series\, which return multip le zeta values as q goes to 1. The space of multiple q-zeta values can be spanned by various different models. In this talk\, we will report on our search for a model that is graded with respect to the usual multiplication of q-series. More precisely\, we are interested in q-series whose generat ing series yield a swap invariant and symmetril bimould. In lowest depth\, these q-series are given by Eisenstein series and their derivatives. Ther efore we call this model the combinatorial multiple Eisenstein series. The construction relies on the bi-brackets introduced by Bachmann\, as well a s a rational solution to the classical double shuffle equations of multipl e zeta values. This talk is based on joint work with H. Bachmann.\n LOCATION:https://researchseminars.org/talk/JENTE/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Alex Saad (University of Oxford) DTSTART:20201124T080000Z DTEND:20201124T083000Z DTSTAMP:20260422T214834Z UID:JENTE/13 DESCRIPTION:Title: M ultiple zeta values and iterated Eisenstein integrals\nby Alex Saad (U niversity of Oxford) as part of Japan Europe Number Theory Exchange Semina r\n\n\nAbstract\nMultiple zeta values (MZVs) are a well-studied class of p eriods that may be described as iterated integrals on the projective line minus three points. Iterated Eisenstein integrals are another class of per iods given as iterated integrals of Eisenstein series along the imaginary axis on the upper half plane. In this talk we sketch a result proving that all MZVs can be expressed as rational linear combinations of iterated Eis enstein integrals by interpreting both classes as periods of fundamental g roups. As a corollary we obtain a new generator for the category of mixed Tate motives over the integers. This work is part of the speaker's PhD the sis\, supervised by F. Brown (Oxford).\n LOCATION:https://researchseminars.org/talk/JENTE/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Minoru Hirose (Kyushu University) DTSTART:20201124T084000Z DTEND:20201124T091000Z DTSTAMP:20260422T214834Z UID:JENTE/14 DESCRIPTION:Title: T he motivic Galois group and alternating multiple zeta values\nby Minor u Hirose (Kyushu University) as part of Japan Europe Number Theory Exchang e Seminar\n\n\nAbstract\nMotivic alternating multiple zeta values are sign ed analogues of motivic multiple zeta values. In this talk\, we introduce alternating analogues of the confluence relations\, and show that they giv e all linear relations among motivic alternating multiple zeta values. Fur thermore we explain that this result gives a complete answer to a Z[1/2] a nalogue of a well-known open conjecture that the motivic Galois group of m ixed Tate motives over Z coincides with Grothendieck-Teichmüller group. T his is a joint work with Nobuo Sato at National Taiwan University.\n LOCATION:https://researchseminars.org/talk/JENTE/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Wataru Takeda (Nagoya University) DTSTART:20201201T080000Z DTEND:20201201T083000Z DTSTAMP:20260422T214834Z UID:JENTE/15 DESCRIPTION:Title: T ranscendence of values of the iterated exponential function at algebraic p oints\nby Wataru Takeda (Nagoya University) as part of Japan Europe Nu mber Theory Exchange Seminar\n\n\nAbstract\nWe study the transcendence of the limit $h(A)$ of the sequence: $A\, A^A\, A^{A^A}\, \\dots $. In 2010 \, Sondow and Marques studied the case that $A$ is rational numbers or alg ebraic numbers satisfying some special conditions. In this talk\, we exten d their results and give an asymptotic formula for the number of algebraic numbers $A$ such that $h(A)$ is algebraic.\nThis is a joint work with Hir otaka Kobayashi and Kota Saito.\n LOCATION:https://researchseminars.org/talk/JENTE/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Sumaia Saad Eddin (JKU Linz) DTSTART:20201201T084000Z DTEND:20201201T091000Z DTSTAMP:20260422T214834Z UID:JENTE/16 DESCRIPTION:Title: R ecent results on Laurent-Stieltjes constants\nby Sumaia Saad Eddin (JK U Linz) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstra ct\nLet $f$ be an arithmetic function and let $\\mathcal{S}^\\#$ denote th e extended Selberg class. We denote by $$\\mathcal{L}(s) = \\sum_{n = 1}^{ \\infty}\\frac{f(n)}{n^s}$$ the Dirichlet series attached to $f$. The Laur ent-Stieltjes constants of $\\mathcal{L}(s)$ which belongs to $\\mathcal{S }^\\#$\, are the coefficients of the Laurent expansion of $\\mathcal{L}$ a t its pole $s=1$. In this talk\, we briefly survey the recent results on t hese constants including our new result\, which is a generalization of man y known results.\nThis is joint work with Sh\\={o}ta Inoue (Nagoya Univers ity) and Ade Irma Suriajaya (Kyushu University).\n LOCATION:https://researchseminars.org/talk/JENTE/16/ END:VEVENT BEGIN:VEVENT SUMMARY:Federico Zerbini (Université Paris-Saclay) DTSTART:20201208T080000Z DTEND:20201208T083000Z DTSTAMP:20260422T214834Z UID:JENTE/17 DESCRIPTION:Title: S ingle-valued multiple zeta values\, and a class of modular forms from stri ng theory\nby Federico Zerbini (Université Paris-Saclay) as part of J apan Europe Number Theory Exchange Seminar\n\n\nAbstract\nSingle-valued mu ltiple zeta values are special values at z=1 of single-valued multiple pol ylogarithms. They form a small subalgebra of the multiple zeta values\, wh ich was first studied in 2013 by Francis Brown and which seems to play an important role in string theory. In particular\, genus-one string theory a mplitudes can be written in terms of a new class of non-holomorphic modula r functions whose asymptotic expansion coefficients are conjectured to be single-valued multiple zeta values. I will introduce this class of functio ns\, known in physics as "modular graph functions"\, and I will report on the proof of the conjecture for "two-point functions"\, obtained last year in collaboration with Don Zagier.\n LOCATION:https://researchseminars.org/talk/JENTE/17/ END:VEVENT BEGIN:VEVENT SUMMARY:Koji Tasaka (Aichi Prefectural University) DTSTART:20201208T084000Z DTEND:20201208T091000Z DTSTAMP:20260422T214834Z UID:JENTE/18 DESCRIPTION:Title: S upercongruence of q-analogues of multiple harmonic sums\nby Koji Tasak a (Aichi Prefectural University) as part of Japan Europe Number Theory Exc hange Seminar\n\n\nAbstract\nI will talk about a q-analogue of the study o f mod p^n congruence relations among multiple harmonic sums. I will also t alk about applications of our study to finite and symmetric multiple zeta values introduced by Kaneko and Zagier.\n LOCATION:https://researchseminars.org/talk/JENTE/18/ END:VEVENT BEGIN:VEVENT SUMMARY:Berend Ringeling (Radboud University Nijmegen) DTSTART:20201215T080000Z DTEND:20201215T083000Z DTSTAMP:20260422T214834Z UID:JENTE/19 DESCRIPTION:Title: S pecial zeta Mahler functions\nby Berend Ringeling (Radboud University Nijmegen) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbst ract\nIn 2009\, H. Akatsuka introduced the zeta Mahler\nfunction (ZMF\, al so called zeta Mahler measure) related to the\nmahler measure.\n Here we discuss a family of ZMFs attached to the Laurent polynomials\n$k + (x_1 + x_1^{-1}) \\cdots (x_r + x_r^{-1})$\, where $k$ is real. We\ngive expli cit formulae\, present examples and establish properties for\nthese ZMFs\, such as an RH-type phenomenon. Further\, we explore relations\nwith the M ahler measure.\n LOCATION:https://researchseminars.org/talk/JENTE/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Ryotaro Harada (National Center for Theoretical Sciences) DTSTART:20201215T084000Z DTEND:20201215T091000Z DTSTAMP:20260422T214834Z UID:JENTE/20 DESCRIPTION:Title: O n the dimension of the space generated by multizeta values in characterist ic p\nby Ryotaro Harada (National Center for Theoretical Sciences) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nIn 1994 \, Don Zagier gave a conjecture about the dimension of the space generated by the power of $2\\pi i$ and double zeta values with fixed weight. In 20 16\, Chieh-Yu Chang tackled this problem in characteristic $p$ case and ob tained a lower bound of the dimension of the space generated by the power of Carlitz period and characteristic $p$ double zeta values with fixed wei ght.\n\nIn this talk\, we prove that the set of characteristic $p$ multize ta values whose indices are "$g$-independent" is a linearly independent se t over the rational function field of characteristic $p$. This gives a gen eralization of Chang’s result to the case of depth greater than 2. \n\nT his is a joint work with Yen-Tsung Chen in National Tsing Hua University.\ n LOCATION:https://researchseminars.org/talk/JENTE/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Shingo Sugiyama (Nihon University) DTSTART:20201222T080000Z DTEND:20201222T083000Z DTSTAMP:20260422T214834Z UID:JENTE/21 DESCRIPTION:Title: L ow-lying zeros of symmetric power L-functions weighted by L-values\nby Shingo Sugiyama (Nihon University) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nThere is a philosophy due to Katz and Sarn ak that low-lying zeros of a family of L-functions should be distributed w ith a density function coming from random matrix theory. This has been sup ported by several evidences on Dirichlet L-functions\, standard L-function s attached to elliptic modular forms\, and so on. In this talk\, we discus s low-lying zeros of symmetric power L-functions attached to Hilbert modul ar forms\, weighted by special values of symmetric square L-functions. We also suggest a conjecture on relations between low-lying zeros and special values of L-functions from our result.\n LOCATION:https://researchseminars.org/talk/JENTE/21/ END:VEVENT BEGIN:VEVENT SUMMARY:Jeanine Van Order (Universität Bielefeld) DTSTART:20201222T084000Z DTEND:20201222T091000Z DTSTAMP:20260422T214834Z UID:JENTE/22 DESCRIPTION:Title: F rom bounds for Fourier coefficients to bounds for Mordell-Weil ranks (and beyond)\nby Jeanine Van Order (Universität Bielefeld) as part of Japa n Europe Number Theory Exchange Seminar\n\n\nAbstract\nMotivated the by th e conjecture of Birch and Swinnerton-Dyer\, I will explain how the spectra l theory of automorphic forms on GL_2 and its two-fold metaplectic cover c an be used to derive unconditional bounds for Mordell-Weil ranks of ellipt ic curves in certain abelian towers of number fields. The surjectivity of the archimedean local Kirillov map (or its classical manifestation in term s of Maass weight raising operators) plays a starring role here\, allowing one to realize the implicit L-values in terms as Fourier-Whittaker coeffi cients of distinct automorphic forms. This leads to both new progress and open questions\, which I will also describe.\n LOCATION:https://researchseminars.org/talk/JENTE/22/ END:VEVENT BEGIN:VEVENT SUMMARY:Shota Inoue (Nagoya University) DTSTART:20210112T080000Z DTEND:20210112T083000Z DTSTAMP:20260422T214834Z UID:JENTE/23 DESCRIPTION:Title: L arge deviations in joint central limit theorems for L-function and their a pplication\nby Shota Inoue (Nagoya University) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nThe independence of L-funct ion is firstly mentioned by Selberg.\nLater Bombieri and Hejhal establishe d the independence by showing the joint central limit theorem of L-functio ns on the critical line.\nIn this talk\, we discuss the large deviations i n the central limit theorem of Bombieri and Hejhal.\nOur results have some consequences of moments of L-functions.\nFor example\, our results lead t o an unconditional lower bound of negative moments of the Riemann zeta-fun ction.\nThe speaker presents these results in this talk. This is joint wor k with Junxian Li (MPIM Bonn)\n LOCATION:https://researchseminars.org/talk/JENTE/23/ END:VEVENT BEGIN:VEVENT SUMMARY:Junxian Li (MPIM Bonn) DTSTART:20210112T084000Z DTEND:20210112T091000Z DTSTAMP:20260422T214834Z UID:JENTE/24 DESCRIPTION:Title: U niform Titchmarsh divisor problems\nby Junxian Li (MPIM Bonn) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nThe Titchmar sh divisor problem asks for an asymptotic evaluation of the\naverage of th e divisor function evaluated at shifted primes. We will discuss how strong error\nterms that are uniform in the shift parameters could be obtained u sing spectral theory of\nautomorphic forms. We will also discuss the autom orphic analogue of the Titchmarsh divisor\nproblem. This is a joint work w ith E. Assing and V. Blome.\n LOCATION:https://researchseminars.org/talk/JENTE/24/ END:VEVENT BEGIN:VEVENT SUMMARY:Gabriele Bogo (TU Darmstadt) DTSTART:20210119T080000Z DTEND:20210119T083000Z DTSTAMP:20260422T214834Z UID:JENTE/25 DESCRIPTION:Title: E xtended modularity and deformation of Riemann surfaces\nby Gabriele Bo go (TU Darmstadt) as part of Japan Europe Number Theory Exchange Seminar\n \n\nAbstract\nI will discuss modular-type functions arising from the class ical theory of uniformizing differential equations and the deformation of Riemann surfaces.\nThese functions are components of vector-valued modular forms associated to extensions of symmetric tensor representations of Fuc hsian groups.\nIn the easiest case\, they can be described in terms of der ivatives of Eichler integrals and quasimodular forms.\n LOCATION:https://researchseminars.org/talk/JENTE/25/ END:VEVENT BEGIN:VEVENT SUMMARY:Nao Komiyama (Nagoya University) DTSTART:20210119T084000Z DTEND:20210119T091000Z DTSTAMP:20260422T214834Z UID:JENTE/26 DESCRIPTION:Title: O n the calculation of moulds\nby Nao Komiyama (Nagoya University) as pa rt of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nThe notio n of moulds was introduced by Jean Ecalle in 1980s\, and he applied moulds to the research of multiple zeta values in the early 2000s. In the mould theory of Ecalle\, alternality\, alternility\,symmetrality and symmetrilit y play an important role. In this talk\, I will explain these properties\, and I will give some calculation examples of these.\n LOCATION:https://researchseminars.org/talk/JENTE/26/ END:VEVENT BEGIN:VEVENT SUMMARY:David Jarossay DTSTART:20210126T080000Z DTEND:20210126T083000Z DTSTAMP:20260422T214834Z UID:JENTE/27 DESCRIPTION:Title: M ultiple harmonic values and adjoint multiple zeta values\nby David Jar ossay as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract \nMultiple harmonic values are adelic lifts of finite multiple zeta values . Adjoint multiple zeta values are certain polynomials of multiple zeta va lues. These two notions arise naturally from the computation of p-adic mul tiple zeta values. We will explain some properties of these objects and a combination of two different period conjectures to describe the properties of multiple harmonic values.\n LOCATION:https://researchseminars.org/talk/JENTE/27/ END:VEVENT BEGIN:VEVENT SUMMARY:Jianqiang Zhao DTSTART:20210126T084000Z DTEND:20210126T091000Z DTSTAMP:20260422T214834Z UID:JENTE/28 DESCRIPTION:Title: A Proof of Kaneko-Tsumura Conjecture on Triple T-Values\nby Jianqiang Z hao as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\n In this talk\, I will describe an approach to discover many weighted sum f ormulas for colored multiple zeta values via generating functions. As appl ications\, I'll present a proof of Kaneko-Tsumura Conjecture on the weight ed sum formula of triple T-values.\n LOCATION:https://researchseminars.org/talk/JENTE/28/ END:VEVENT BEGIN:VEVENT SUMMARY:Anthony Poels (Nihon University/Paris-Saclay & ENS Lyon) DTSTART:20210202T080000Z DTEND:20210202T083000Z DTSTAMP:20260422T214834Z UID:JENTE/29 DESCRIPTION:Title: R ational approximation to real points on quadratic hypersurfaces\nby An thony Poels (Nihon University/Paris-Saclay & ENS Lyon) as part of Japan Eu rope Number Theory Exchange Seminar\n\n\nAbstract\nTo each point of R^n we attach an exponent of approximation which quantifies "how well" we can ap proximate this point by rational points with same denominator. A fundament al question in Diophantine approximation is to determine the supremum of t his exponent on given subsets of R^n. In a joint work with Roy\, we recen tly answered this question for quadratic hypersurfaces Z of R^n defined ov er Q: the optimal exponent depends only on the Witt index (over Q) of the quadratic form defining Z. In dimension n = 2\, we recover results of Roy while in higher dimension this completes recent work of Kleinbock and Mos hchevitin.\n LOCATION:https://researchseminars.org/talk/JENTE/29/ END:VEVENT BEGIN:VEVENT SUMMARY:Makoto Kawashima (Nihon University) DTSTART:20210202T084000Z DTEND:20210202T091000Z DTSTAMP:20260422T214834Z UID:JENTE/30 DESCRIPTION:Title: L inear forms in polylogarithms\nby Makoto Kawashima (Nihon University) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nWe s hall discuss a recent joint work with Sinnou David and Noriko Hirata. In t his talk\, we introduce a linear independence criterion of values of gener alized Lerch functions. By this criterion\, we obtain new linear independe nce results on the values of polylogarithms at distinct points over an alg ebraic number field. This is done via a construction of an explicit system of Padé apppoximants of generalized Lerch functions.\n LOCATION:https://researchseminars.org/talk/JENTE/30/ END:VEVENT BEGIN:VEVENT SUMMARY:Hidekazu Furusho (Nagoya University) DTSTART:20210601T080000Z DTEND:20210601T083000Z DTSTAMP:20260422T214834Z UID:JENTE/31 DESCRIPTION:Title: A rtin-Schreier equation and Carlitz multiple polylogarithms\nby Hidekaz u Furusho (Nagoya University) as part of Japan Europe Number Theory Exchan ge Seminar\n\n\nAbstract\nI will propose a method of analytic continuation of multiple polylogarithms in positive characteristic by making use of th e Artin-Schreier equation.\n LOCATION:https://researchseminars.org/talk/JENTE/31/ END:VEVENT BEGIN:VEVENT SUMMARY:Erik Panzer (University of Oxford) DTSTART:20210601T083500Z DTEND:20210601T090500Z DTSTAMP:20260422T214834Z UID:JENTE/32 DESCRIPTION:Title: S ingle-valued integrals over discs\nby Erik Panzer (University of Oxfor d) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nI will briefly explain how integrals over moduli spaces of marked discs app ear in deformation quantization. The talk will then recap the single-value d integration procedure of Brown and Schnetz\, explain the difference due to the presence of the disc boundary\, and hence how 'non-single valued mu ltiple zeta values' appear as single-valued integrals. This is joint work with Brent Pym and Peter Banks\, https://arxiv.org/abs/1812.11649.\n LOCATION:https://researchseminars.org/talk/JENTE/32/ END:VEVENT BEGIN:VEVENT SUMMARY:Riccardo Pengo (École Normale Supérieure de Lyon) DTSTART:20210608T080000Z DTEND:20210608T083000Z DTSTAMP:20260422T214834Z UID:JENTE/33 DESCRIPTION:Title: M ahler measure of successively exact polynomials\nby Riccardo Pengo (É cole Normale Supérieure de Lyon) as part of Japan Europe Number Theory Ex change Seminar\n\n\nAbstract\nThe relation between Mahler measures of poly nomials and special values of L-functions has been widely explored since t he seminal works of Boyd\, Deninger and Rodriguez-Villegas in the late '90 s. Sometimes\, as in the earliest examples computed by Smyth\, these relat ions occur between Mahler measures of n-variable polynomials and special v alues associated to geometric objects of dimension strictly less than n-1. This phenomenon has found a first explanation in the notion of exactness\ , put forward by Maillot and Lalín. In this talk\, based on joint work in progress with François Brunault\, we will give a survey of these questio ns\, and explain how one can interpret them using new cohomological approa ches\, which provide a notion of successive exactness\, predicted by Lalí n\, that explains the observed drops in the dimension of the geometric obj ects used to construct the L-functions whose special values should be rela ted to the Mahler measure of the polynomial in question.\n LOCATION:https://researchseminars.org/talk/JENTE/33/ END:VEVENT BEGIN:VEVENT SUMMARY:Jun Ueki (Tokyo Denki University) DTSTART:20210608T083500Z DTEND:20210608T090500Z DTSTAMP:20260422T214834Z UID:JENTE/34 DESCRIPTION:Title: I wasawa theory for knots\nby Jun Ueki (Tokyo Denki University) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nWe recall th e analogy between the Alexander-Fox theory of Z-covers of knots and the Iw asawa theory for cyclotomic Zp-extensions\n\nand discuss how pro-p theory for knots can be interesting. (Partially joint work with Ryoto Tange and H yuga Yoshizaki.)\n LOCATION:https://researchseminars.org/talk/JENTE/34/ END:VEVENT BEGIN:VEVENT SUMMARY:Ade Irma Suriajaya (Kyushu University) DTSTART:20210615T080000Z DTEND:20210615T083000Z DTSTAMP:20260422T214834Z UID:JENTE/35 DESCRIPTION:Title: G oldbach representations and exceptional zeros of Dirichlet L-functions \nby Ade Irma Suriajaya (Kyushu University) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nG. H. Hardy and J. E. Littlewood i n 1922 studied the number of representations of a positive number as a sum of prime numbers. They conjectured that all large even numbers can be wri tten as a sum of two odd primes and also conjectured an asymptotic formula for the number of representations. This conjecture gives a quantitative s tatement of the well-known Goldbach's conjecture. J. Fei in 2016 used a we aker form of this Hardy-Littlewood Goldbach's Conjecture and showed that w e could almost eliminate the possible existence of the Landau-Siegel zeros of Dirichlet L-functions associated with characters modulo q congruent to 3 mod 4. To be more precise\, Fei showed that we can narrow the interval which may contain a possible exceptional zero of the corresponding Dirichl et L-function. G. Bhowmik and K. Halupczok in a recent preprint extended F ei's result to all odd characters with a slightly weaker conjecture. Indep endently\, C. Jia in his recent preprint used a slightly different form of weak Hardy-Littlewood Goldbach's Conjecture to obtain results similar to Bhowmik and Halupczok's. We extended the weak Hardy-Littlewood Goldbach's Conjecture as close as possible to the original Hardy-Littlewood Goldbach' s Conjecture and improved the arguments to extend Fei\, Bhowmik and Halupc zok\, and Jia's results to all Dirichlet L-functions associated with real quadratic characters. This is a joint work with Daniel A. Goldston.\n\nFol lowing Goldston's talk at an AIM seminar early last month\, J. Friedlander and H. Iwaniec further improved our result and succeeded in showing that the weak Hardy-Littlewood Goldbach's Conjecture we used indeed implies tha t there are no Landau-Siegel zeros. As in Friedlander and Iwaniec's approa ch\, using an improved estimate on the prime number theorem for primes in arithmetic progressions\, we are able to further improve our arguments to obtain Friedlander and Iwaniec's result. In this talk\, I would like to ex plain the slightly different conjectures and approaches used in this study and introduce relevant results.\n LOCATION:https://researchseminars.org/talk/JENTE/35/ END:VEVENT BEGIN:VEVENT SUMMARY:Tanja Isabelle Schindler (Centro di Ricerca Matematica Ennio De Gi orgi) DTSTART:20210615T083500Z DTEND:20210615T090500Z DTSTAMP:20260422T214834Z UID:JENTE/36 DESCRIPTION:Title: A central limit theorem for the Birkhoff sum of the Riemann zeta-function o ver a Boolean type transformation\nby Tanja Isabelle Schindler (Centro di Ricerca Matematica Ennio De Giorgi) as part of Japan Europe Number The ory Exchange Seminar\n\n\nAbstract\nWe prove a central limit theorem for t he real and imaginary part and the absolute value of the Riemann zeta-func tion ξ sampled along a vertical line in the critical strip with respect t o an ergodic transformation similar to the Boolean transformation\, i.e. w e have an ergodic transformation T: R->R and consider ξ(c+i T^n(x)) for d ifferent n and fixed c and x. Our results complement results by Steuding w ho has first studied this system and has proven a strong law of large numb ers. As a side result we state a general central limit theorem for a class of unbounded observables on the real line over the same ergodic transform ation. With that it is possible that the results can be generalized to oth er L-function.\n LOCATION:https://researchseminars.org/talk/JENTE/36/ END:VEVENT BEGIN:VEVENT SUMMARY:Adam Keilthy (Max Planck Institute for Mathematics) DTSTART:20210622T080000Z DTEND:20210622T083000Z DTSTAMP:20260422T214834Z UID:JENTE/37 DESCRIPTION:Title: B lock graded relations among multiple zeta values\nby Adam Keilthy (Max Planck Institute for Mathematics) as part of Japan Europe Number Theory E xchange Seminar\n\n\nAbstract\nBased on the results of Charlton\, we intro duce a new filtration on the space of motivic multiple zeta values\, calle d the block filtration. Considering the associated graded algebra\, we are able to provide a complete set of explicit generators for the block grade d motivic Lie algebra and establish several new families of (block graded) relations\, including a new shuffle relation\, a dihedral symmetry\, and mysterious differential relation. Furthermore\, we can show that\, in low block degree\, these provide a complete set of relations among motivic mul tiple zeta values.\n LOCATION:https://researchseminars.org/talk/JENTE/37/ END:VEVENT BEGIN:VEVENT SUMMARY:Masataka Ono (Waseda University) DTSTART:20210622T083500Z DTEND:20210622T090500Z DTSTAMP:20260422T214834Z UID:JENTE/38 DESCRIPTION:Title: F inite and symmetric multiple zeta values associated with 2-colored rooted trees\nby Masataka Ono (Waseda University) as part of Japan Europe Num ber Theory Exchange Seminar\n\n\nAbstract\nIn my recent study\, we introdu ced so called 2-colored rooted tree\, which is a kind of combinatorial obj ect\, and finite multiple zeta values associated with it\, and gave a form ula of them in terms of the usual finite multiple zeta values. From the vi ewpoint of Kaneko–Zagier conjecture\, it is expected that there exists a n analogous theory for the symmetric multiple zeta values.\n\nIn this talk \, we review the theory of finite multiple zeta values associated with 2-c olored rooted trees\, and we give a symmetric counterpart. Moreover\, we g ive the analogous formula for them in terms of the usual symmetric multipl e zeta values. If time permits\, we explain that the same formula holds in the harmonic algebra. This talk is partially based on the joint work with Shin-ichiro Seki and Shuji Yamamoto.\n LOCATION:https://researchseminars.org/talk/JENTE/38/ END:VEVENT BEGIN:VEVENT SUMMARY:Yoshihiro Takeyama (University of Tsukuba) DTSTART:20210629T080000Z DTEND:20210629T083000Z DTSTAMP:20260422T214834Z UID:JENTE/39 DESCRIPTION:Title: D erivations on the algebra of multiple harmonic q-series\nby Yoshihiro Takeyama (University of Tsukuba) as part of Japan Europe Number Theory Exc hange Seminar\n\n\nAbstract\nBradley proved that a q-analogue model of mul tiple zeta values (MZVs) satisfies Ohno's relation for MZVs in the same fo rm. As a corollary\, we see that it also satisfies the derivation relation s. In this talk we define derivations on the algebra of multiple harmonic q-series which contains various q-analogue models of MZVs\, and show that they generate linear relations among the q-series.\n LOCATION:https://researchseminars.org/talk/JENTE/39/ END:VEVENT BEGIN:VEVENT SUMMARY:Dominique Manchon (CNRS & Université Clermont-Auvergne) DTSTART:20210629T083500Z DTEND:20210629T090500Z DTSTAMP:20260422T214834Z UID:JENTE/40 DESCRIPTION:Title: A n infinitesimal bialgebra related to multiple polylogarithms and q-multipl e zeta values\nby Dominique Manchon (CNRS & Université Clermont-Auve rgne) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract \nMultiple polylogarithms as well as some models of q-multiple zeta values (e.g. the Ohno-Okuda-Zudilin model) make sense for integer arguments of a ny sign. They are encoded by words with three letters p\,d\,y subject to p d=dp=1. We describe a comultiplication on the linear span of these words\, which gives rise together with concatenation to an infinitesimal bialgebr a structure. Then we will explore the compatibility of this comultiplicati on with the mixed-sign versions of the shuffle product. Based on joint wor ks with J. Castillo-Medina\, K. Ebrahimi-Fard and J. Singer.\n LOCATION:https://researchseminars.org/talk/JENTE/40/ END:VEVENT BEGIN:VEVENT SUMMARY:Steven Charlton (Universität Hamburg) DTSTART:20210706T080000Z DTEND:20210706T083000Z DTSTAMP:20260422T214834Z UID:JENTE/41 DESCRIPTION:Title: F unctional equations for Nielsen polylogarithms\nby Steven Charlton (Un iversität Hamburg) as part of Japan Europe Number Theory Exchange Seminar \n\n\nAbstract\nThe Nielsen polylogarithms $S_{p\,q}$ are perhaps the simp lest examples of higher depth multiple polylogarithms\, but beyond some si mple symmetries\, relatively little seems to be known about their identiti es and functional relations. I will report on some joint work with Herber t Gangl\, and Danylo Radchenko\, wherein we establish that $S_{3\,2}$ sati sfies the dilogarithm 5-term relation\, modulo explicit $\\operatorname{Li }_5$ terms. From this we can always extract corresponding results for $S_ {3\,2}$ whenever a dilogarithm identity is accessible through the 5-term r elation. I will also try to give a flavour of some of our results and eva luations in higher weight.\n LOCATION:https://researchseminars.org/talk/JENTE/41/ END:VEVENT BEGIN:VEVENT SUMMARY:Shuji Yamamoto (Keio University) DTSTART:20210706T083500Z DTEND:20210706T090500Z DTSTAMP:20260422T214834Z UID:JENTE/42 DESCRIPTION:Title: S um formulas of Schur multiple zeta values of ribbon shape\nby Shuji Ya mamoto (Keio University) as part of Japan Europe Number Theory Exchange Se minar\n\n\nAbstract\nThe classical sum formula states that the sum of mult iple zeta(-star) values of fixed weight and depth is an integer multiple o f the Riemann zeta value.\nSince the Schur multiple zeta value is a common generalization of multiple zeta and zeta-star values\, it is interesting if we have a similar formula for the sum of Schur multiple zeta values of fixed weight and shape. In this talk\, we will present some results on suc h sums for ribbon shape. This is a joint work with H. Bachmann\, S. Kadota \, Y. Suzuki and Y. Yamasaki.\n LOCATION:https://researchseminars.org/talk/JENTE/42/ END:VEVENT BEGIN:VEVENT SUMMARY:Sven Möller (RIMS Kyoto) DTSTART:20210713T080000Z DTEND:20210713T083000Z DTSTAMP:20260422T214834Z UID:JENTE/43 DESCRIPTION:Title: V ector-valued Eisenstein series and classification of holomorphic vertex op erator algebras\nby Sven Möller (RIMS Kyoto) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nVertex operator algebras (VO As) axiomatise 2-dim. conformal field theoories in physics and are at the centre of remarkable conections\nbetween representation and number theory (e.g. Monstrous Moonshine).\n\nIndeed\, through their characters/graded di mensions\, VOAs are intimately connected with various types of modular for ms.\n\nIn this work we study identities for holomorphic VOAs of central ch arge 24 based on a pairing argument with vector-valued Eisenstein series o f\nweight 2. The thus obtained dimension formulae are then used to prove a classification result for these VOAs\, which had been open for thirty yea rs.\n LOCATION:https://researchseminars.org/talk/JENTE/43/ END:VEVENT BEGIN:VEVENT SUMMARY:Claudia Alfes-Neumann (Bielefeld University) DTSTART:20210713T083500Z DTEND:20210713T090500Z DTSTAMP:20260422T214834Z UID:JENTE/44 DESCRIPTION:Title: E lliptic curves and harmonic weak Maass forms\nby Claudia Alfes-Neumann (Bielefeld University) as part of Japan Europe Number Theory Exchange Sem inar\n\n\nAbstract\nIn this talk we first introduce modular forms and an a rithmetically particularly interesting generalization: harmonic weak Maass forms. We show how these forms can be related to elliptic curves. Special harmonic Maass forms encode the vanishing of the central L-value and L-de rivative which occur in the Birch and Swinnerton-Dyer Conjecture. (This is in parts joint work with Michael Griffin\, Ken Ono and Larry Rolen buildi ng upon work of Jan Bruinier an Ken Ono.)\n LOCATION:https://researchseminars.org/talk/JENTE/44/ END:VEVENT BEGIN:VEVENT SUMMARY:Hanneke Wiersema (King's College London) DTSTART:20210720T080000Z DTEND:20210720T083000Z DTSTAMP:20260422T214834Z UID:JENTE/45 DESCRIPTION:Title: O n a BSD-type formula for L-values of Artin twists of elliptic curves\n by Hanneke Wiersema (King's College London) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nThe Birch and Swinnerton-Dyer conj ecture connects the arithmetic of elliptic curves over number fields to th eir L-functions. The conjecture includes a formula for the leading term of the Taylor series of the L-function at s=1 in terms of arithmetic data as sociated to the elliptic curve. In this talk we will discuss the possible existence of such a formula for L-functions of elliptic curves twisted by Artin representations. After outlining some expected properties of these L -functions\, we will present arithmetic applications and some explicit exa mples. This is joint work with Vladimir Dokchitser and Robert Evans.\n LOCATION:https://researchseminars.org/talk/JENTE/45/ END:VEVENT BEGIN:VEVENT SUMMARY:Yukako Kezuka (Max Planck Institute for Mathematics) DTSTART:20210720T083500Z DTEND:20210720T090500Z DTSTAMP:20260422T214834Z UID:JENTE/46 DESCRIPTION:Title: O n the 2-rank of the ideal class group of cubic fields and its relation to 2-Selmer groups\nby Yukako Kezuka (Max Planck Institute for Mathematic s) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nI n this talk\, I will introduce a family of elliptic curves with complex mu ltiplication and explain what the conjecture of Birch and Swinnerton-Dyer says for these curves. I will study the 3-part of the conjecture\, and pre sent a non-triviality condition relating the 2-part of the ideal class gro up of certain cubic field extensions and the 2-Selmer group of the ellipti c curves. This is joint work with Yongxiong Li.\n LOCATION:https://researchseminars.org/talk/JENTE/46/ END:VEVENT BEGIN:VEVENT SUMMARY:Hideki Murahara (University of Kitakyushu) DTSTART:20211026T080000Z DTEND:20211026T090000Z DTSTAMP:20260422T214834Z UID:JENTE/47 DESCRIPTION:Title: O n the linear relations among the parametrized multiple series\nby Hide ki Murahara (University of Kitakyushu) as part of Japan Europe Number Theo ry Exchange Seminar\n\n\nAbstract\nThe parametrized multiple series are ge neralizations of multiple zeta values introduced by Igarashi. In this talk \, the speaker would like to show a new relation among them. More precisel y\, he will show the following two statements: the linear part of the Kawa shima relation of multiple zeta values is generalized to the parametrized multiple series\, and any linear relations among parametrized multiple ser ies can be written as a linear combination of this relation. This is joint work with Minoru Hirose in Nagoya University and Tomokazu Onozuka in Kyus hu University.\n LOCATION:https://researchseminars.org/talk/JENTE/47/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin Brindle (University of Cologne) DTSTART:20211026T084000Z DTEND:20211026T091000Z DTSTAMP:20260422T214834Z UID:JENTE/48 DESCRIPTION:Title: A pplications of marked partitions to qMZVs\nby Benjamin Brindle (Univer sity of Cologne) as part of Japan Europe Number Theory Exchange Seminar\n\ n\nAbstract\nIn this talk\, we introduce the notion of marked partitions a nd explain some of their relationships to q-analogues of multiple zeta val ues (qMZVs). Marked partitions are partitions where each row and column of the corresponding Young diagram can be marked with one color. We interpre t qMZVs as generating a series of marked partitions. With this concept\, w e can visualize and prove\, for example\, the so-called Schlesinger-Zudili n duality. Furthermore\, we show that the generating series of the number of conjugacy classes of GL(n\,K) for a finite field K is given by the gene rating series of certain Ohno-Okuda-Zudilin qMZVs.\n LOCATION:https://researchseminars.org/talk/JENTE/48/ END:VEVENT BEGIN:VEVENT SUMMARY:Quentin Gazda (Université Lyon 1) DTSTART:20211102T080000Z DTEND:20211102T090000Z DTSTAMP:20260422T214834Z UID:JENTE/49 DESCRIPTION:Title: A lgebraic independence of Carlitz’s polylogarithms\nby Quentin Gazda (Université Lyon 1) as part of Japan Europe Number Theory Exchange Semina r\n\n\nAbstract\nOver function fields\, Carlitz polylogarithms are the cou nterpart of classical polylogarithms. The algebraic relations among values of Carlitz polylogarithms were studied by many authors\, including Anders on\, Thakur\, Papanikolas\, Chang and Yu. In this talk\, I will discuss th e new informations one can collect on this subject from « t-Motivic Cohom ology »\, a tool introduced in my thesis akin to the cohomology of hypoth etical (classical) mixed motives.\n LOCATION:https://researchseminars.org/talk/JENTE/49/ END:VEVENT BEGIN:VEVENT SUMMARY:Hohto Bekki (Keio University) DTSTART:20211102T083500Z DTEND:20211102T090500Z DTSTAMP:20260422T214834Z UID:JENTE/50 DESCRIPTION:Title: O n some applications of an integral formula of Hurwitz\nby Hohto Bekki (Keio University) as part of Japan Europe Number Theory Exchange Seminar\n \n\nAbstract\nIn this talk I would like to discuss mainly two topics both related to a classical integral formula of Hurwitz which is also known as the Feynman parametrization. First I would like to report on the construct ion of a new Eisenstein cocycle called the Shintani-Barnes cocycle which g ives a cohomological description of the values of zeta functions of genera l number fields at positive integers. Then I would like to explain an obse rvation towards the applications of such a description. More precisely\, I would like to discuss a relationship between the values of zeta functions of totally real fields and a kind of conical zeta values.\n LOCATION:https://researchseminars.org/talk/JENTE/50/ END:VEVENT BEGIN:VEVENT SUMMARY:Miyu Suzuki (Kanazawa University) DTSTART:20211109T080000Z DTEND:20211109T090000Z DTSTAMP:20260422T214834Z UID:JENTE/51 DESCRIPTION:Title: E xplicit mean value formula for periods and L-functions\nby Miyu Suzuki (Kanazawa University) as part of Japan Europe Number Theory Exchange Semi nar\n\n\nAbstract\nI will present an explicit mean value formula for the c entral values of twisted modular L-functions. This is a special case of th e general result for automorphic representations of GL(2) and its inner fo rms. For the proof\, we introduce a certain zeta function associated wit h a perhomogeneous vector space. I also present some numerical examples of our mean value formulas. This talk is based on a joint work with Satoshi Wakatsuki and Shun'ichi Yokoyama.\n LOCATION:https://researchseminars.org/talk/JENTE/51/ END:VEVENT BEGIN:VEVENT SUMMARY:Andreas Mono (University of Cologne) DTSTART:20211109T083500Z DTEND:20211109T090500Z DTSTAMP:20260422T214834Z UID:JENTE/52 DESCRIPTION:Title: O n a twisted version of Zagier's $f_{k\,D}$ function\nby Andreas Mono ( University of Cologne) as part of Japan Europe Number Theory Exchange Semi nar\n\n\nAbstract\nWe present a twisting of Zagier’s $f_{k\,D}$ function by a sign function and a genus character. Assuming even and positive inte gral weight\, we inspect its obstruction to modularity\, and compute its F ourier expansion. This involves twisted hyperbolic Eisenstein series\, loc ally harmonic Maaß forms\, and modular cycle integrals\, which were studi ed by Duke\, Imamoglu\, Tóth. Lastly\, we outline some applications of ou r results to theta lifts of Poincaré series.\n LOCATION:https://researchseminars.org/talk/JENTE/52/ END:VEVENT BEGIN:VEVENT SUMMARY:Ulf Kühn (Universität Hamburg) DTSTART:20211116T080000Z DTEND:20211116T090000Z DTSTAMP:20260422T214834Z UID:JENTE/53 DESCRIPTION:Title: R ealizations of the formal double Eisenstein space\nby Ulf Kühn (Unive rsität Hamburg) as part of Japan Europe Number Theory Exchange Seminar\n\ n\nAbstract\nIn this talk\, we introduce the formal double Eisenstein spac e $\\mathcal{E}_k$\, which is a generalization of the formal double zeta s pace $\\mathcal{D}_k$ of Gangl-Kaneko-Zagier. We show that $\\mathbb{Q}$-l inear from $\\mathcal{E}_k$ to $A$\, for some $\\mathbb{Q}$-algebra $A$\, can be constructed from formal Laurent series that satisfy the Fay identit y. As the prototypical example\, we define the Kronecker realization\, whi ch lifts Gangl-Kaneko-Zagier's Bernoulli realization\, and whose image con sists of quasimodular forms for the full modular group. As an application to the theory of modular forms\, we obtain a purely combinatorial proof of Ramanujan's differential equations for classical Eisenstein series. This talk is based on a joint work with H. Bachmann and N. Matthes.\n LOCATION:https://researchseminars.org/talk/JENTE/53/ END:VEVENT BEGIN:VEVENT SUMMARY:Shingo Saito (Kyushu University) DTSTART:20211116T083500Z DTEND:20211116T090500Z DTSTAMP:20260422T214834Z UID:JENTE/54 DESCRIPTION:Title: S um formulas for multiple zeta values and symmetric multiple zeta values\nby Shingo Saito (Kyushu University) as part of Japan Europe Number Theo ry Exchange Seminar\n\n\nAbstract\nThe sum formulas for multiple zeta(-sta r) values and symmetric multiple zeta(-star) values bear a striking resemb lance. We explain the resemblance in a rather straightforward manner using an identity that involves the Schur multiple zeta values. We also give a common generalization of the sum formulas in terms of generating functions . This is joint work with Minoru Hirose and Hideki Murahara.\n LOCATION:https://researchseminars.org/talk/JENTE/54/ END:VEVENT BEGIN:VEVENT SUMMARY:Ryomei Iwasa (University of Copenhagen) DTSTART:20211123T080000Z DTEND:20211123T090000Z DTSTAMP:20260422T214834Z UID:JENTE/55 DESCRIPTION:Title: C ohomology theories of schemes and algebraic K-theory\nby Ryomei Iwasa (University of Copenhagen) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nI’ll discuss what is a cohomology theory of schem es. Examples should include étale cohomology\, crystalline cohomology\, d e Rham cohomology\, algebraic K-theory\, topological cyclic homology\, and so forth. Then I’ll explain calculation of cohomology of $\\operatornam e{BGL}_n$ and its application to algebraic K-theory. This talk is based on a joint work in progress with Toni Annala.\n LOCATION:https://researchseminars.org/talk/JENTE/55/ END:VEVENT BEGIN:VEVENT SUMMARY:Axel Kölschbach (MPIM Bonn) DTSTART:20211123T083500Z DTEND:20211123T090500Z DTSTAMP:20260422T214834Z UID:JENTE/56 DESCRIPTION:Title: O n a candidate for the p-adic Jacquet—Langlands correspondence\nby Ax el Kölschbach (MPIM Bonn) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nThe Jacquets—Langlands correspondence is a biject ion between square-integrable complex representations of $\\operatorname{G L}_n(F)$ (for $F$ a finite extension of $\\mathbb{Q}_p$) and square-integr able $f$ complex representations of the unit group of the division algebra $D$ over $F$ with invariant $1/n$. Using the cohomology of the Lubin—Ta te Tower\, Scholze constructed a candidate for a $p$-adic Jacquets—Langl ands correspondence. We will explain this construction and explore the rel ationship to the cohomology of Harris—Taylor Shimura varieties.\n LOCATION:https://researchseminars.org/talk/JENTE/56/ END:VEVENT BEGIN:VEVENT SUMMARY:Luigi Pagano (University of Copenhagen) DTSTART:20211130T080000Z DTEND:20211130T090000Z DTSTAMP:20260422T214834Z UID:JENTE/57 DESCRIPTION:Title: M otivic zeta functions of Hilbert schemes of points on surfaces\nby Lui gi Pagano (University of Copenhagen) as part of Japan Europe Number Theory Exchange Seminar\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/JENTE/57/ END:VEVENT BEGIN:VEVENT SUMMARY:Shun'ichi Yokoyama (Tokyo Metropolitan University) DTSTART:20211130T083500Z DTEND:20211130T090500Z DTSTAMP:20260422T214834Z UID:JENTE/58 DESCRIPTION:Title: J ulia language for number theory\nby Shun'ichi Yokoyama (Tokyo Metropol itan University) as part of Japan Europe Number Theory Exchange Seminar\n\ nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/JENTE/58/ END:VEVENT BEGIN:VEVENT SUMMARY:Naganori Yamaguchi (RIMS Kyoto) DTSTART:20211207T083500Z DTEND:20211207T090500Z DTSTAMP:20260422T214834Z UID:JENTE/59 DESCRIPTION:Title: T he m-step solvable anabelian geometry for hyperbolic curves over finitely generated fields\nby Naganori Yamaguchi (RIMS Kyoto) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nIn anabelian geometry \, there is a conjecture\, called Grothendieck's conjecture (i.e. can we r econstruct group-theoretically a hyperbolic curve from its etale fundament al group?). This conjecture has been solved in the affirmative in many cas es. Regarding this conjecture\, if we replace the fundamental group with i ts maximal m-step solvable quotient\, then does the conjecture still hold? (Write m-GC for this question). \nm-GC has rarely been proved\, and we on ly have three previous studies (Nakamura\, Mochizuki). In this talk\, I e xplain the content of these conjectures and of the previous studies. In pa rticular\, I explain a recent result that solves m-GC for affine hyperboli c curves over finitely generated fields.\n LOCATION:https://researchseminars.org/talk/JENTE/59/ END:VEVENT BEGIN:VEVENT SUMMARY:Benjamin Collas (RIMS Kyoto) DTSTART:20211207T080000Z DTEND:20211207T083000Z DTSTAMP:20260422T214834Z UID:JENTE/60 DESCRIPTION:Title: A nabelian geometry\, a modern overview\nby Benjamin Collas (RIMS Kyoto) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nThe question of reconstructing certain classes of geometric spaces from their étale fundamental group is part of Grothendieck's legacy. While it is of ten considered for his original insight to have been fulfilled in the '90s (Nakamura\, Tamagawa and Mochizuki)\, it also became a definite area of e xpertise of the Japanese arithmetic geometry school: new techniques and pr inciples have been developed that go beyond Grothendieck's original insigh t.\n\nThe goal of this talk is to present a broad overview of principles a nd techniques of the field\, including some prospective links with motivic theory and some recent Diophantine applications (Mochizuki\; Mochizuki\, Hoshi et al.)\n LOCATION:https://researchseminars.org/talk/JENTE/60/ END:VEVENT BEGIN:VEVENT SUMMARY:Francesco Campagna (University of Copenhagen/MPIM Bonn) DTSTART:20211214T080000Z DTEND:20211214T083000Z DTSTAMP:20260422T214834Z UID:JENTE/61 DESCRIPTION:Title: P rimes of cyclic reduction for elliptic curves\nby Francesco Campagna ( University of Copenhagen/MPIM Bonn) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nGiven an elliptic curve E over a number fi eld F and a prime of good reduction p\, the group of rational points on th e reduced curve E mod p is abelian on at most two generators. If one gener ator suffices\, we call p a prime of cyclic reduction for E. In this talk I will explain why the set of primes of cyclic reduction for E should have a natural density and I will discuss the possible vanishing of this densi ty. This is a joint work with Peter Stevenhagen.\n LOCATION:https://researchseminars.org/talk/JENTE/61/ END:VEVENT BEGIN:VEVENT SUMMARY:Yoshinori Mishiba (University of the Ryukyus) DTSTART:20211214T083500Z DTEND:20211214T090500Z DTSTAMP:20260422T214834Z UID:JENTE/62 DESCRIPTION:Title: O n relations among v-adic multiple zeta values over function fields\nby Yoshinori Mishiba (University of the Ryukyus) as part of Japan Europe Num ber Theory Exchange Seminar\n\n\nAbstract\nLet v be a finite place of the rational function field over a finite field. The v-adic multiple zeta valu es (MZV's) are v-adic analogues of Thakur's infinity-adic MZV's. In this t alk\, we will discuss linear/algebraic relations among them. In particular \, we show that the v-adic MZV's satisfy the same algebraic relations that their corresponding infinity-adic MZV's satisfy. We will also discuss a d imension conjecture and candidates of generators for v-adic MZV's. This is an ongoing joint work with Chieh-Yu Chang and Yen-Tsung Chen.\n LOCATION:https://researchseminars.org/talk/JENTE/62/ END:VEVENT BEGIN:VEVENT SUMMARY:Kenji Sakugawa (Shinshu University) DTSTART:20211221T080000Z DTEND:20211221T090000Z DTSTAMP:20260422T214834Z UID:JENTE/63 DESCRIPTION:Title: O n the R-mixed Hodge structure on the relative pro-unipotent fundamental gr oup of M_{1\,1}\nby Kenji Sakugawa (Shinshu University) as part of Jap an Europe Number Theory Exchange Seminar\n\n\nAbstract\nLet M_{1\,1} be th e moduli stack of elliptic curves. The relative pro-unipotent fundamental group of M_{1\,1} is a Tannakian fundamental group classifying local syste ms over M_{1\,1} whose simple factors are isomorphic to relative middle co homology groups of open Kuga-Sato varieties over M_{1\,1}. The mixed Hodge structure on it was first defined in a more general context by Hain\, and more detailed studies have recently been started by Hain and Brown. In th is talk\, we will discuss real mixed Hodge structure on the relative pro- unipotent fundamental group in length two.\n LOCATION:https://researchseminars.org/talk/JENTE/63/ END:VEVENT BEGIN:VEVENT SUMMARY:Joshua Drewitt (University of Nottingham) DTSTART:20211221T083500Z DTEND:20211221T090500Z DTSTAMP:20260422T214834Z UID:JENTE/64 DESCRIPTION:Title: L aplace-eigenvalue equations for the space of modular iterated integrals\nby Joshua Drewitt (University of Nottingham) as part of Japan Europe Nu mber Theory Exchange Seminar\n\n\nAbstract\nOne motivation for the definit ion of real analytic modular forms was due to their relation to modular gr aph functions. In this talk\, we will provide a brief introduction to the space real analytic modular forms and then focus on the subspace of modula r iterated integrals. In particular\, we will look at the Laplace-eigenval ue equations associated to length two and length three modular iterated in tegrals. We will also discuss how these functions relate to the modular gr aph functions arising from string perturbation theory.\n LOCATION:https://researchseminars.org/talk/JENTE/64/ END:VEVENT BEGIN:VEVENT SUMMARY:Huajie Li (MPIM Bonn) DTSTART:20220118T080000Z DTEND:20220118T083000Z DTSTAMP:20260422T214834Z UID:JENTE/65 DESCRIPTION:Title: I ntroduction to the relative trace formulae of Guo-Jacquet\nby Huajie L i (MPIM Bonn) as part of Japan Europe Number Theory Exchange Seminar\n\n\n Abstract\nGuo and Jacquet have proposed a conjecture generalising Waldspur ger’s well-known theorem relating toric periods to central values of aut omorphic L-functions for $GL(2)$. A promising tool to attack this conjectu re is the relative trace formula. Although the formula has not been establ ished in full generality\, its simple version has been used to prove some cases of Guo-Jacquet’s conjecture. In this talk\, we shall introduce the background of their conjecture and survey some known results obtained via the relative trace formula. In the end\, we shall also mention our study of some problems arising from this approach.\n LOCATION:https://researchseminars.org/talk/JENTE/65/ END:VEVENT BEGIN:VEVENT SUMMARY:Ratko Darda (University of Osaka) DTSTART:20220118T084000Z DTEND:20220118T091000Z DTSTAMP:20260422T214834Z UID:JENTE/66 DESCRIPTION:Title: M anin-Peyre conjecture for weighted projective stacks\nby Ratko Darda ( University of Osaka) as part of Japan Europe Number Theory Exchange Semina r\n\n\nAbstract\nManin-Peyre conjecture predicts the number of rational po ints of bounded height on algebraic varieties. The constants appearing in the prediction are expressed using arithmetic and geometric invariants of the variety. It is natural to ask if the constants appearing in some other arithmetic counting results\, like counting elliptic curves of bounded na ive or Faltings height or counting Galois extensions with fixed Galois gro up G of bounded discriminant\, could be explained in a similar way. But th ese objects are not parametrized by a variety but by an algebraic stack. I n this talk\, we will be focused on weighted projective stacks (the stacky quotients (A^n-{0})/Gm for a weighted action)\, when a complete theory of Manin-Peyre conjecture can be provided. This explains all the constants f or the elliptic curves and some of the constants when G=\\mu_m is the grou p of m-th roots of unity.\n LOCATION:https://researchseminars.org/talk/JENTE/66/ END:VEVENT BEGIN:VEVENT SUMMARY:Sho Tanimoto (Nagoya University) DTSTART:20220125T080000Z DTEND:20220125T083000Z DTSTAMP:20260422T214834Z UID:JENTE/67 DESCRIPTION:Title: C ampana points\, Height zeta functions\, and log Manin’s conjecture\n by Sho Tanimoto (Nagoya University) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nManin’s conjecture predicts the asymptot ic formula for the counting function of rational points of bounded height on smooth Fano varieties. There is also some study on Manin’s conjecture for integral points\, however several subtleties prevent a general formul ation of log Manin’s conjecture for integral points. Campana and Abramov ich introduced the notion of Campana points which interpolates between rat ional points and integral points\, and Pieropan\, Smeets\, Varilly-Alvarad o and the author proposed a formulation of log Manin’s conjecture for Ca mpana points. In this talk\, I will discuss this conjecture and an approac h to it using the height zeta function.\n LOCATION:https://researchseminars.org/talk/JENTE/67/ END:VEVENT BEGIN:VEVENT SUMMARY:Fabien Pazuki (University of Copenhagen) DTSTART:20220125T084000Z DTEND:20220125T091000Z DTSTAMP:20260422T214834Z UID:JENTE/68 DESCRIPTION:Title: N orthcott property for special values of L-functions\nby Fabien Pazuki (University of Copenhagen) as part of Japan Europe Number Theory Exchange Seminar\n\n\nAbstract\nPick an integer n. Consider a natural family of obj ects\, such that each object $X$ in the family has an L-function $L(X\,s)$ . If we assume that the collection of special values $L*(X\,n)$ is bounded \, does it imply that the family of objects is finite? We will first expla in why we consider this question\, in link with Kato's heights of mixed mo tives\, and give two recent results. This is joint work with Riccardo Peng o.\n LOCATION:https://researchseminars.org/talk/JENTE/68/ END:VEVENT END:VCALENDAR