BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Arnaud Beauville (Université de Nice) DTSTART:20200429T140000Z DTEND:20200429T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/1 DESCRIPTION:Title: Vector bundles on Fano threefolds and K3 surfaces\nby Arnaud Be auville (Université de Nice) as part of HU Berlin algebraic geometry semi nar\n\nAbstract: TBA\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Daniel Erman (University of Wisconsin - Madison) DTSTART:20200506T140000Z DTEND:20200506T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/2 DESCRIPTION:Title: Limits of polynomials rings\nby Daniel Erman (University of Wis consin - Madison) as part of HU Berlin algebraic geometry seminar\n\n\nAbs tract\nI will discuss two ways to think about a limit of a\npolynomial rin g in $n$ variables as $n$ goes to infinity\, and how this can\nbe used to study complexity problems in algebraic geometry. This is\njoint work with Steven V Sam and Andrew Snowden.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Riccardo Salvati Manni (Università degli studi di Roma "La Sapien za") DTSTART:20200513T140000Z DTEND:20200513T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/3 DESCRIPTION:Title: The Kodaira dimension of the moduli space of abelian varieties of d imension 6.\nby Riccardo Salvati Manni (Università degli studi di Rom a "La Sapienza") as part of HU Berlin algebraic geometry seminar\n\nAbstra ct: TBA\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Patrick Brosnan (University of Maryland) DTSTART:20200520T140000Z DTEND:20200520T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/4 DESCRIPTION:Title: Fixed points in toroidal compactifications and essential dimension of covers.\nby Patrick Brosnan (University of Maryland) as part of HU Berlin algebraic geometry seminar\n\n\nAbstract\nWe (Najmuddin Fakhruddin and I) prove a fixed point theorem for the action of certain local monodro my groups on etale covers and use it to deduce lower bounds on essential d imension of covers. In particular\, we can give geometric proofs of many ( but definitely not all) of the results in a recent preprint of Farb\, Kisi n and Wolfson. Moreover\, we can extend their incompressibility results fo r Hodge type Shimura varieties to certain Shimura varieties for E7 (those with 0-dimensional rational boundary components).\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Mihnea Popa (Northwestern University) DTSTART:20200610T150000Z DTEND:20200610T160000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/5 DESCRIPTION:Title: Minimal exponents of singularities\nby Mihnea Popa (Northwester n University) as part of HU Berlin algebraic geometry seminar\n\n\nAbstrac t\nThe minimal exponent of a function is the negative of the largest root of its reduced Bernstein-Sato polynomial. It refines the notion of log can onical threshold\, and it is related (sometimes conjecturally) to other in teresting objects\, for instance the Igusa zeta function. I will describe some results towards understanding minimal exponents\, based on viewing th em in the context of D-modules and Hodge theory on one hand\, and biration al geometry on the other. This is joint work with Mircea Mustata.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Egor Yasinsky (Universität Basel) DTSTART:20200624T140000Z DTEND:20200624T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/6 DESCRIPTION:Title: Cremona groups and their subgroups\nby Egor Yasinsky (Universit ät Basel) as part of HU Berlin algebraic geometry seminar\n\n\nAbstract\n The Cremona group is a group of birational automorphisms of a projective s pace. Its study goes back to classical works of Cremona\, Noehter\, Castel nuovo and Bertini\, and it has been a subject of very intensive research d uring the last 15 years. This study employs different techniques - from mo dern birational geometry (e.g. Mori theory\, Sarkisov program\, and Cauche r Birkar's works) to geometric group theory. In this talk\, I will try to overview three plots on Cremona groups: classification of finite subgroups \, topological properties\, infinite subgroups and quotients of Cremona gr oups.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Yuri Tschinkel (New York University) DTSTART:20200617T140000Z DTEND:20200617T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/7 DESCRIPTION:Title: Equivariant birational geometry\nby Yuri Tschinkel (New York Un iversity) as part of HU Berlin algebraic geometry seminar\n\n\nAbstract\nI will discuss new invariants in equivariant birational geometry (joint wor k with Kontsevich and Pestun).\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Rahul Pandharipande (ETH Zürich) DTSTART:20200701T130000Z DTEND:20200701T140000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/8 DESCRIPTION:Title: The moduli spaces of differentials on curves\nby Rahul Pandhari pande (ETH Zürich) as part of HU Berlin algebraic geometry seminar\n\n\nA bstract\nThe moduli space of pairs $(C\,f)$ where $C$ is a curve and $f$ i s a rational function leads to the well-developed theory of Hurwitz spaces . The study of the moduli of $(C\,\\omega)$ where $C$ is a curve and $\\om ega$ is a meromorphic differential is a younger subject. I will discuss re cent developments in the study of the moduli spaces of holomorphic/meromor phic differentials on curves. Many of the basic questions about cycle clas ses and integrals have now been solved (through the work of many people) - - but there are also several interesting open directions.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Adrien Sauvaget (Université de Cergy Pontoise) DTSTART:20200527T140000Z DTEND:20200527T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/9 DESCRIPTION:Title: Moduli spaces of large pluricanonical divisors\nby Adrien Sauva get (Université de Cergy Pontoise) as part of HU Berlin algebraic geometr y seminar\n\n\nAbstract\nWe consider the moduli spaces of curves endowed w ith a $k$-canonical divisor. The purpose of the talk is to explain that th e geometry of moduli spaces of metric surfaces can be studied by consideri ng the large $k$-behavior of these moduli spaces. The first application of this strategy is a proof of the finiteness of the volumes of moduli space s of flat surfaces with conical singularities. The second one is a conject ure on the volumes of moduli spaces of hyperbolic cone surfaces.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/9/ END:VEVENT BEGIN:VEVENT SUMMARY:András Lőrincz (Humboldt-Universität zu Berlin) DTSTART:20200603T140000Z DTEND:20200603T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/10 DESCRIPTION:Title: Equivariant D-modules\nby András Lőrincz (Humboldt-Universit ät zu Berlin) as part of HU Berlin algebraic geometry seminar\n\n\nAbstra ct\nIn this talk\, I will discuss some results concerning equivariant\nD-m odules. Under suitable finiteness conditions\, the category of such\nobjec ts on a stratification is equivalent to the category of\nfinite-dimensiona l representations of a quiver. We describe such\nquivers explicitly for so me irreducible representations of complex\nreductive groups and toric vari eties. In these cases we use the\nresults to find the explicit D-module st ructure of local cohomology\nmodules supported in orbit closures. Other ap plications include\nLyubeznik numbers and intersection cohomology groups o f orbit\nclosures.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Mircea Mustaţă (University of Michigan) DTSTART:20200617T151500Z DTEND:20200617T161500Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/11 DESCRIPTION:Title: Minimal exponents of hypersurfaces and a conjecture of Teissier\nby Mircea Mustaţă (University of Michigan) as part of HU Berlin algeb raic geometry seminar\n\n\nAbstract\nThe minimal exponent of a hypersurfac e is a refinement of the log canonical threshold\, a fundamental\ninvarian t of singularities in birational geometry. After a brief introduction to t hese invariants\, I will discuss work on\na conjecture of Teissier\, relat ing the invariant of a hypersurface with that of a hyperplane section. Thi s is joint work\n(partially in progress) with Eva Elduque and Bradley Dirk s.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Elisabetta Colombo DTSTART:20200708T140000Z DTEND:20200708T150000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/12 DESCRIPTION:Title: The dimension of the Voisin sets in the moduli space of abelian va rieties\nby Elisabetta Colombo as part of HU Berlin algebraic geometry seminar\n\n\nAbstract\nI will discuss reseach in collaboration with Naran jo and\nPirola on the subsets $V_k(A)$ of an abelian variety $A$\, consist ing of\nthose points $x$ such that the\nzero-cycle $x-O$ is $k$-nilpotent with respect to the Pontryaghin product.\nThese sets were initially introd uced and studied by Claire Voisin. We\nfind a sharp upper bound of the dim ension in moduli of the locus of\nthose abelian varieties $A$ for which $V _2(A)$ is positive dimensional.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Alexandru Suciu DTSTART:20200715T150000Z DTEND:20200715T160000Z DTSTAMP:20260422T230719Z UID:HUBerlinAlgGeo/13 DESCRIPTION:Title: Poincaré duality and cohomology jump loci\nby Alexandru Suciu as part of HU Berlin algebraic geometry seminar\n\n\nAbstract\nThe cohomo logy jump loci of a space $X$ are of two basic\ntypes: the characteristic varieties\, defined in terms of homology with coefficients in rank one loc al systems\, and the resonance varieties\, constructed from information en coded in either the cohomology ring\, or an algebraic model for $X$. We w ill explore in this talk the geometry of these varieties and the delicate interplay between them in the context of compact\, orientable 3-manifolds. In the process\, we will arrive at a fairly precise geometric descriptio n of the resonance varieties $R^i_k(A)$ of a 3-dimensional Poincaré duali ty algebra $A$.\n LOCATION:https://researchseminars.org/talk/HUBerlinAlgGeo/13/ END:VEVENT END:VCALENDAR