BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Ana Caraiani
DTSTART:20200529T143000Z
DTEND:20200529T153000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/1
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/1/">
 Vanishing theorems for the cohomology of Shimura varieties</a>\nby Ana Car
 aiani as part of Cross Atlantic Representation Theory and Other topics ONl
 ine (CARTOON) conference\n\n\nAbstract\nI will survey some vanishing theor
 ems for the mod $p$ cohomology of Shimura varieties. I will mention some $
 p$-adic results and some $\\ell$-adic results\, where $\\ell$ is a prime d
 ifferent from $p$. Both settings rely on the geometry of the Hodge-Tate pe
 riod morphism. I will highlight the differently flavoured techniques that 
 are needed using the toy model of the modular curve. I will end by discuss
 ing joint work in progress with Matteo Tamiozzo in the case of Hilbert mod
 ular varieties.\n
LOCATION:https://researchseminars.org/talk/CARTOON/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yiannis Sakellaridis
DTSTART:20200530T143000Z
DTEND:20200530T153000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/2
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/2/">
 Intersection cohomology & $L$-functions</a>\nby Yiannis Sakellaridis as pa
 rt of Cross Atlantic Representation Theory and Other topics ONline (CARTOO
 N) conference\n\n\nAbstract\nI will report on ongoing joint work with Jona
 than Wang\, relating the intersection complex of the arc space of a spheri
 cal variety to an unramified local $L$-function. This is a broad generaliz
 ation of Tate's thesis ($G=\\mathbb G_m$\, $X=\\mathbb A^1$)\, where the l
 ocal unramified $L$-factors are represented by the characteristic function
  of the integers $\\mathfrak o$ of a non-Archimedean field. For more gener
 al groups $G$ and possibly singular spherical $G$-varieties $X$\, the char
 acteristic function of $X(\\mathfrak o)$ is not the correct object to cons
 ider\, and has to be replaced by a function obtained as the Frobenius trac
 e of the intersection complex of the arc space of $X$. In special cases of
  horospherical\, toric\, affine homogeneous spherical varieties\, or certa
 in reductive monoids\, the relation of this function to $L$-functions was 
 previously described in works of Braverman--Finkelberg--Gaitsgory--Mirkovi
 &cacute\;\, Bouthier--Ng&ocirc\; and myself. Our current work describes th
 ese IC functions in a very general setting\, relating the IC function of t
 he arc space to an $L$-value determined by the geometry of the spherical v
 ariety.\n
LOCATION:https://researchseminars.org/talk/CARTOON/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eva Viehmann
DTSTART:20200531T143000Z
DTEND:20200531T153000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/3
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/3/">
 Newton strata in the weakly admissible locus</a>\nby Eva Viehmann as part 
 of Cross Atlantic Representation Theory and Other topics ONline (CARTOON) 
 conference\n\n\nAbstract\nGiven a reductive group $G$ over a $p$-adic loca
 l field and a minuscule cocharacter\, Rapoport and Zink constructed an ope
 n subspace inside the associated adic flag variety\, called $p$-adic perio
 d domain\, or weakly admissible locus. These are vast generalizations of D
 rinfeld upper half spaces. Recently\, Caraiani and Scholze defined a Newto
 n stratification on adic flag varieties. The unique open Newton stratum\, 
 which coincides with the so-called admissible locus\, is contained in the 
 weakly admissible locus\, but is in most cases strictly smaller. For the g
 roup $\\textnormal{GL}_n$\, I describe which of the other Newton strata in
 tersect the weakly admissible locus.\n
LOCATION:https://researchseminars.org/talk/CARTOON/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alex Youcis
DTSTART:20200531T160000Z
DTEND:20200531T162000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/4
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/4/">
 An approach to characterizing the local Langlands conjecture over $p$-adic
  fields</a>\nby Alex Youcis as part of Cross Atlantic Representation Theor
 y and Other topics ONline (CARTOON) conference\n\n\nAbstract\nIn 2013 P. S
 cholze provided an alternative proof of the local Langlands correspondence
  (LLC) for $\\textnormal{GL}_n$ and\, in doing so\, Scholze gave a new cha
 racterization of the LLC via a certain trace identity. In this talk the sp
 eaker will discuss joint work with A. Bertoloni Meli showing that a genera
 lization of this trace identity characterizes the LLC for much more genera
 l groups if one assumes standard expected properties of such a corresponde
 nce.\n
LOCATION:https://researchseminars.org/talk/CARTOON/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Adèle Bourgeois
DTSTART:20200529T160000Z
DTEND:20200529T162000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/5
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/5/">
 Restricting representations via restricting $G$-data and Kim-Yu types</a>\
 nby Adèle Bourgeois as part of Cross Atlantic Representation Theory and O
 ther topics ONline (CARTOON) conference\n\n\nAbstract\nLet $\\mathbb{G}$ b
 e a reductive group defined over a $p$-adic field $F$\, and let $G = \\mat
 hbb{G}(F)$. We assume that $\\mathbb{G}$ splits over a tamely ramified ext
 ension of $F$ and that the residual characteristic $p$ of $F$ does not div
 ide the order of the Weyl group of $\\mathbb{G}$. Under this assumption\, 
 Fintzen showed that all irreducible supercuspidal representations of $G$ a
 re obtained via the J.K.~Yu construction. From a $G$-datum $\\Psi$\, the J
 .K.~Yu construction produces an irreducible supercuspidal representation o
 f $G$\, which we denote by $\\pi_G(\\Psi)$. \n\nGiven a reductive $F$-subg
 roup $\\mathbb{H}$ that contains the derived subgroup of $\\mathbb{G}$\, w
 e study the restriction $\\pi_G(\\Psi)|_H$ and obtain a description of its
  decomposition into irreducible components along with their multiplicities
 . We achieve this by describing a natural restriction process from which w
 e construct $H$-data from the $G$-datum $\\Psi$. \n\nTo study the restrict
 ion to $H$ of irreducible representations of $G$ which are not supercuspid
 al\, one can use the theory of types. More specifically\, given the underl
 ying assumption on $p$\, Fintzen showed that every irreducible representat
 ion of $G$ contains a Kim-Yu type. The construction of Kim-Yu types is ver
 y similar to Yu's construction of supercuspidal representations. As such\,
  we can define an analogous restriction process from which we construct Ki
 m-Yu types for $H$ from a Kim-Yu type for $G$\, therefore obtaining inform
 ation on the restriction to $H$ of any irreducible representation of $G$.\
 n
LOCATION:https://researchseminars.org/talk/CARTOON/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Zhilin Luo
DTSTART:20200529T163000Z
DTEND:20200529T165000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/6
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/6/">
 On the stable transfer for $\\textrm{Sym}^n$ lifting of $\\textrm{GL}_2$: 
 Archimedean case</a>\nby Zhilin Luo as part of Cross Atlantic Representati
 on Theory and Other topics ONline (CARTOON) conference\n\n\nAbstract\nFoll
 owing the paradigm of R. Langlands\, we are going to explore the the stabl
 e transfer factors for $\\textnormal{Sym}^{n}$ lifting from $\\textnormal{
 GL}_{2}$ to $\\textnormal{GL}_{n+1}$. We give a complete answer for temper
 ed principal series over any local fields of characteristic zero\, which i
 n particular resolve the case over complex field. Over real field\, when $
 n$ is odd\, we provide a reduction formula\, reducing the construction of 
 the stable transfer factors to diagonal embedding of $\\textnormal{GL}_{2}
 $ to finitely many copies of $\\textnormal{GL}_{2}$. There are also partia
 l results over $p$-adic fields.\n\nThis is a joint work with D. Johnstone.
  Preprint available arXiv:2002.09551.\n
LOCATION:https://researchseminars.org/talk/CARTOON/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Pol van Hoften
DTSTART:20200530T160000Z
DTEND:20200530T162000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/7
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/7/">
 Mod $p$ points on Shimura varieties of parahoric level</a>\nby Pol van Hof
 ten as part of Cross Atlantic Representation Theory and Other topics ONlin
 e (CARTOON) conference\n\n\nAbstract\nThe conjecture of Langlands-Rapoport
  gives a conjectural description of the mod $p$ points of Shimura varietie
 s\, with applications towards computing the (semi-simple) zeta function of
  these Shimura varieties. The conjecture was proven by Kisin for abelian t
 ype Shimura varieties at primes of (hyperspecial) good reduction\, after h
 aving constructed smooth integral models. For primes of (parahoric) bad re
 duction\, Kisin and Pappas have constructed `good' integral models and the
  conjecture naturally generalises to this setting. In this talk we will di
 scuss work in progress towards the conjecture for these integral models\, 
 under some hypotheses\, building on earlier work of Zhou.\n
LOCATION:https://researchseminars.org/talk/CARTOON/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rahul Dalal
DTSTART:20200530T163000Z
DTEND:20200530T165000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/8
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/8/">
 Statistics of Automorphic Representations through Simplified Trace Formula
 s</a>\nby Rahul Dalal as part of Cross Atlantic Representation Theory and 
 Other topics ONline (CARTOON) conference\n\n\nAbstract\nAutomorphic forms 
 are very difficult to study individually so it is often good to study them
  in families instead. The Arthur-Selberg trace formula is a powerful tool 
 for this. For certain very nice families (discrete series at infinity) the
  trace formula takes on a simpler form\, allowing us to much more easily p
 rove distributional results. I will discuss some of these results.\n
LOCATION:https://researchseminars.org/talk/CARTOON/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hanneke Wiersema
DTSTART:20200531T163000Z
DTEND:20200531T165000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/9
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/9/">
 Serre's conjecture and two notions of minimal weight</a>\nby Hanneke Wiers
 ema as part of Cross Atlantic Representation Theory and Other topics ONlin
 e (CARTOON) conference\n\n\nAbstract\nThe strong form of Serre's conjectur
 e states that every two-dimensional continuous\, odd\, irreducible mod $p$
  Galois representation arises from a modular form of a specific minimal we
 ight\, level and character. We will see how one can use modular representa
 tion theory to prove the minimal weight is equal to a notion of minimal we
 ight inspired by the recipe for weights introduced by Buzzard\, Diamond an
 d Jarvis. We will also briefly touch on generalisations of this\, again us
 ing modular representation theory\, which is the subject of work in progre
 ss.\n
LOCATION:https://researchseminars.org/talk/CARTOON/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tasho Kaletha
DTSTART:20200531T180000Z
DTEND:20200531T190000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/10
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/10/"
 >A twisted Yu construction and Harish-Chandra characters</a>\nby Tasho Kal
 etha as part of Cross Atlantic Representation Theory and Other topics ONli
 ne (CARTOON) conference\n\n\nAbstract\nIn 2001 J.K.Yu gave a general const
 ruction of supercuspidal representations of reductive $p$-adic groups. It 
 was shown by Kim and Fintzen that all supercuspidal representations arise 
 from it when $p$ is not too small. I will discuss a twist of this construc
 tion\, which resolves a recently discovered error in Yu's paper. I will th
 en discuss the following applications that this twisted construction makes
  possible: (i) a formula for the Harish-Chandra character of the resulting
  representations without compactness or shallowness assumptions\, (ii) a c
 onstruction of the local Langlands correspondence for arbitrary supercuspi
 dal parameters when $p$ is not too small\, (iii) the proof of endoscopic t
 ransfer for regular supercuspidal L-packets. This is joint work\, partly i
 n progress\, with Fintzen and Spice.\n
LOCATION:https://researchseminars.org/talk/CARTOON/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John Bergdall\, Melody Chan\, Pol van Hoften\, Kim Klinger-Logan\,
  and Lillian Pierce
DTSTART:20200529T180000Z
DTEND:20200529T190000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/11
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/11/"
 >Local panel: How individuals are dealing with the pandemic</a>\nby John B
 ergdall\, Melody Chan\, Pol van Hoften\, Kim Klinger-Logan\, and Lillian P
 ierce as part of Cross Atlantic Representation Theory and Other topics ONl
 ine (CARTOON) conference\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/CARTOON/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tim Gowers\, Michael Harris\, Jaclyn Lang\, Monica Nevins\, and Ji
 ll Pipher
DTSTART:20200530T180000Z
DTEND:20200530T190000Z
DTSTAMP:20260417T100432Z
UID:CARTOON/12
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/CARTOON/12/"
 >Global panel: Challenges the math community faces in the future</a>\nby T
 im Gowers\, Michael Harris\, Jaclyn Lang\, Monica Nevins\, and Jill Pipher
  as part of Cross Atlantic Representation Theory and Other topics ONline (
 CARTOON) conference\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/CARTOON/12/
END:VEVENT
END:VCALENDAR