BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Zhuang He (HU Berlin)
DTSTART:20201104T140000Z
DTEND:20201104T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/1
DESCRIPTION:Title: Birational geometry of blow-ups of the projective space along li
near subspaces and automorphisms of Kummer surfaces\nby Zhuang He (HU
Berlin) as part of Humboldt Algebraic Geometry Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Krämer (HU Berlin)
DTSTART:20201111T140000Z
DTEND:20201111T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/2
DESCRIPTION:Title: Semicontinuity of Gauss maps and the Schottky problem\nby Th
omas Krämer (HU Berlin) as part of Humboldt Algebraic Geometry Seminar\n\
nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michael Kemeny (Wisconsin)
DTSTART:20201118T150000Z
DTEND:20201118T160000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/3
DESCRIPTION:Title: Minimal rank generators for syzygies of canonical curves\nby
Michael Kemeny (Wisconsin) as part of Humboldt Algebraic Geometry Seminar
\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicola Tarasca (Virginia)
DTSTART:20201125T140000Z
DTEND:20201125T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/4
DESCRIPTION:Title: Motivic classes of degeneracy loci and pointed Brill-Noether var
ieties\nby Nicola Tarasca (Virginia) as part of Humboldt Algebraic Geo
metry Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gaetan Borot (HU Berlin)
DTSTART:20201202T140000Z
DTEND:20201202T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/5
DESCRIPTION:Title: ELSV and topological recursion for double Hurwitz numbers\nb
y Gaetan Borot (HU Berlin) as part of Humboldt Algebraic Geometry Seminar\
n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lawrence Ein
DTSTART:20201209T150000Z
DTEND:20201209T160000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/6
DESCRIPTION:Title: Singularities and syzygies of secant varieties of curves\nby
Lawrence Ein as part of Humboldt Algebraic Geometry Seminar\n\nAbstract:
TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yohan Brunebarbe
DTSTART:20201216T140000Z
DTEND:20201216T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/7
DESCRIPTION:Title: Increasing hyperbolicity of varieties supporting a variation of
Hodge structures with level structures\nby Yohan Brunebarbe as part of
Humboldt Algebraic Geometry Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ignacio Barros (Paris-Saclay)
DTSTART:20210113T140000Z
DTEND:20210113T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/8
DESCRIPTION:Title: On the irrationality of moduli spaces of K3 surfaces\nby Ign
acio Barros (Paris-Saclay) as part of Humboldt Algebraic Geometry Seminar\
n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ruijie Yang (Stony Brook)
DTSTART:20210113T151500Z
DTEND:20210113T161500Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/9
DESCRIPTION:Title: Decomposition theorem for semisimple local systems\nby Ruiji
e Yang (Stony Brook) as part of Humboldt Algebraic Geometry Seminar\n\nAbs
tract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Frederik Benirschke (Stony Brook)
DTSTART:20210120T140000Z
DTEND:20210120T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/10
DESCRIPTION:Title: Boundary of linear subvarieties\nby Frederik Benirschke (St
ony Brook) as part of Humboldt Algebraic Geometry Seminar\n\nAbstract: TBA
\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yeuk Hay Joshua Lam (Harvard)
DTSTART:20210120T151500Z
DTEND:20210120T161500Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/11
DESCRIPTION:Title: Calabi-Yau varieties and Shimura varieties\nby Yeuk Hay Jos
hua Lam (Harvard) as part of Humboldt Algebraic Geometry Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dawei Chen (Boston College)
DTSTART:20210210T140000Z
DTEND:20210210T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/12
DESCRIPTION:Title: Connected components of the space of k-differentials\nby Da
wei Chen (Boston College) as part of Humboldt Algebraic Geometry Seminar\n
\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Claire Voisin (College de France)
DTSTART:20210217T140000Z
DTEND:20210217T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/13
DESCRIPTION:Title: Schiffer variations of hypersurfaces and the generic Torelli th
eorem\nby Claire Voisin (College de France) as part of Humboldt Algebr
aic Geometry Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carl Lian (HU Berlin)
DTSTART:20210303T140000Z
DTEND:20210303T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/14
DESCRIPTION:Title: Non-tautological and H-tautological Hurwitz cycles\nby Carl
Lian (HU Berlin) as part of Humboldt Algebraic Geometry Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Giacomo Mezzedimi (Hannover)
DTSTART:20210127T140000Z
DTEND:20210127T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/15
DESCRIPTION:Title: The Kodaira dimension of some moduli spaces of elliptic K3 surf
aces\nby Giacomo Mezzedimi (Hannover) as part of Humboldt Algebraic Ge
ometry Seminar\n\nAbstract: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Leonardo Lerer (Paris-Saclay)
DTSTART:20210106T140000Z
DTEND:20210106T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/16
DESCRIPTION:Title: Cohomology jump loci on singular varieties\nby Leonardo Ler
er (Paris-Saclay) as part of Humboldt Algebraic Geometry Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrey Soldatenkov (HU Berlin)
DTSTART:20210414T140000Z
DTEND:20210414T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/17
DESCRIPTION:Title: Holonomy of the Obata connection on hypercomplex manifolds\
nby Andrey Soldatenkov (HU Berlin) as part of Humboldt Algebraic Geometry
Seminar\n\n\nAbstract\nThe algebra of quaternions has been a focus of atte
ntion in many branches of mathematics ever since its introduction by Hamil
ton. One may think that quaternions form a noncommutative finite extension
of the field of complex numbers. For a geometer\, it is natural to wonder
if there exists a suitable notion of a quaternionic variety\, analogous t
o a complex algebraic variety. I will try to give an introduction to this
circle of ideas\, explain how one can approach quaternionic (or hypercompl
ex) geometry and what natural problems arise in this context. One importan
t notion in hypercomplex geometry is the Obata connection\, the unique tor
sion-free connection that preserves the action of the quaternions. I will
present some results on the study of its holonomy.\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alessandro Verra (Universita Roma Tre)
DTSTART:20210421T140000Z
DTEND:20210421T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/18
DESCRIPTION:Title: The Igusa quartic and the Prym map\nby Alessandro Verra (Un
iversita Roma Tre) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbs
tract\nThe Igusa\, or the Castelnuovo-Richmond quartic is a famous hypersu
rface of the complex projective 4-space known for its ubiquity in algebrai
c geometry. It is related to the Prym map $P$ in genus 6. As is well know
n the map $P$ has degree 27 and dominates the moduli space of 5-dimensiona
l principally polarized abelian varieties. Other maps with the same monod
romy are associated to $P$ and reflect related configurations. Among these
these of particular importance is the map $J: D \\rightarrow A_5$\, with
fibre the configuration of double sixes of lines of the cubic surface. We
describe $J$ geometrically\, showing that it is birationally equivalent t
o the period map for the moduli space $D$ of 30-nodal quartic threefolds\
, cutting twice a quadratic section of the Igusa quartic.\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hannah Larson (Stanford University)
DTSTART:20210428T150000Z
DTEND:20210428T160000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/19
DESCRIPTION:Title: The rational Chow rings of $M_7$\, $M_8$\, and $M_9$\nby Ha
nnah Larson (Stanford University) as part of Humboldt Algebraic Geometry S
eminar\n\n\nAbstract\nThe rational Chow ring of the moduli space $M_g$ of
curves of genus $g$ is known for $g \\leq 6$. In each of these cases\, the
Chow ring is tautological (generated by certain natural classes known as
kappa classes). In recent joint work with Sam Canning\, we prove that the
rational Chow ring of $M_g$ is tautological for $g = 7\, 8\, 9$\, thereby
determining the Chow rings by work of Faber. In this talk\, I will give an
overview of our approach\, with particular focus on the locus of tetragon
al curves (special curves admitting a degree 4 map to $\\mathbb{P}^1$).\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mina Aganagic (University of California Berkeley)
DTSTART:20210512T150000Z
DTEND:20210512T160000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/20
DESCRIPTION:Title: Khovanov Homology from Mirror Symmetry\nby Mina Aganagic (U
niversity of California Berkeley) as part of Humboldt Algebraic Geometry S
eminar\n\n\nAbstract\nKhovanov showed\, more than 20 years ago\, that ther
e is a deeper theory underlying the Jones polynomial. The “knot categori
fication problem” is to find a uniform description of this theory\, for
all gauge groups\, which originates from physics\, or geometry. I will des
cribe two solutions to this problem\, which I recently discovered\, relate
d by a version of two dimensional (homological) mirror symmetry. The theor
ies are significantly more efficient than the algebraic descriptions mathe
maticians have found\, even in the Khovanov homology case.\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rahul Pandharipande (ETH Zürich)
DTSTART:20210526T140000Z
DTEND:20210526T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/21
DESCRIPTION:Title: Tevelev degrees and Hurwitz moduli spaces\nby Rahul Pandhar
ipande (ETH Zürich) as part of Humboldt Algebraic Geometry Seminar\n\n\nA
bstract\nI will explain various numerical and cohomological questions rela
ted to Hurwitz moduli spaces (including older results with Faber on tautol
ogical classes and newer calculations with Cela and Schmitt on Tevelev deg
rees).\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Salim Tayou (Harvard University)
DTSTART:20210519T150000Z
DTEND:20210519T160000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/22
DESCRIPTION:Title: Equidistribution of Hodge loci\nby Salim Tayou (Harvard Uni
versity) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbstract\nGiv
en a polarized variation of Hodge structures\, it is a classical result th
at the Hodge locus is a countable union of proper algebraic subvarieties.
In this talk\, I will explain a general equidistribution theorem for these
Hodge loci and explain several applications: equidistribution of higher c
odimension Noether-Lefschetz loci\, equidistribution of Hecke translates o
f a curve in $A_g$ and equidistribution of some families of CM points in S
himura varieties. The results of this talk are joint work with Nicolas Tho
lozan.\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:François Greer (Stony Brook University)
DTSTART:20210505T140000Z
DTEND:20210505T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/23
DESCRIPTION:Title: A tale of two Severi curves\nby François Greer (Stony Broo
k University) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbstract
\nLet $(S\,L)$ be a general polarized K3 surface of degree $2g-2$. A gener
al member of the linear system $|L|\\simeq \\mathbb P^g$ is a smooth curve
of genus $g$. For $0\\leq h\\leq g$\, define the Severi variety $V_h(S\,L
)\\subset |L|$ to be the locus of curves with geometric genus $\\leq h$. A
s expected\, $V_h(S\,L)$ has dimension $h$. We consider the case $h=1$\, w
here the Severi variety is a (singular) curve. Our first result is that th
e geometric genus of $V_1(S\,L)$ goes to infinity with $g$\; we give a low
er bound $\\sim e^{c\\sqrt{g}}$. Next we consider the analogous question f
or Severi curves of a rational elliptic surface\, and give a polynomial up
per bound instead. Modular forms play a central role in both arguments.\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gerard Freixas i Montplet (IMJ-PRG)
DTSTART:20210616T140000Z
DTEND:20210616T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/24
DESCRIPTION:Title: Complex Chern-Simons and the first tautological class\nby G
erard Freixas i Montplet (IMJ-PRG) as part of Humboldt Algebraic Geometry
Seminar\n\n\nAbstract\nIn this talk I will propose a construction of the c
omplex Chern-Simons line bundle\, in the context of a family of compact Ri
emann surfaces and a relative moduli space of flat vector bundles on it. T
he construction is inspired by Deligne's functorial interpretation of Arak
elov geometry\, where direct images of characteristic classes of hermitian
vector bundles are lifted to the level of hermitian line bundles. In our
setting\, hermitian metrics are replaced by flat relative connections\, an
d non-abelian Hodge theory is a fundamental tool in the approach. We will
discuss some properties of the complex Chern-Simons line bundle\, and an a
pplication to a differential geometric incarnation of the first tautologic
al class on the moduli space of curves. This is joint work with Dennis Eri
ksson and Richard Wentworth.\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Holmes (University of Leiden)
DTSTART:20210602T140000Z
DTEND:20210602T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/26
DESCRIPTION:Title: The double-double ramification cycle\nby David Holmes (Univ
ersity of Leiden) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbst
ract\nA basic question in the geometry of Riemann surfaces is to decide wh
en a given divisor of degree 0 is the divisor of a rational function (is p
rincipal). In the 19th century Abel and Jacobi gave a beautiful solution:
one writes the divisor as the boundary of a 1-cycle\, and the divisor is p
rincipal if and only if every holomorphic differential integrates to zero
against this cycle. From a modern perspective it is natural to allow the c
urve and divisor to vary in a family\, perhaps allowing the curve to degen
erate to a singular (stable) curve so that the corresponding moduli space
is compact. The double ramification cycle can then be seen as a virtual fu
ndamental class of the locus in the moduli space of curves over which our
divisor becomes principal. We will focus on two basic questions: where doe
s the double ramification cycle naturally live\, and what happens when we
intersect two double ramification cycles? We will see why (logarithmically
) blowing up the moduli space can make life easier. This is joint work wit
h Rosa Schwarz\, building on earlier joint work with Aaron Pixton and Joha
nnes Schmitt.\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea di Lorenzo (HU Berlin)
DTSTART:20210609T140000Z
DTEND:20210609T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/27
DESCRIPTION:Title: The integral Chow ring of the stack of stable 1-pointed curves
of genus two\nby Andrea di Lorenzo (HU Berlin) as part of Humboldt Alg
ebraic Geometry Seminar\n\n\nAbstract\nModuli stacks of curves play a prom
inent role in algebraic geometry. In particular\, their rational Chow ring
s have been the subject of intensive research in the last forty years\, si
nce Mumford first investigated the subject. There is also a well defined n
otion of integral Chow ring for these stacks: this is more refined\, but a
lso much harder to compute. In this talk I will present the computation of
the integral Chow ring of the stack of stable 1-pointed curves of genus t
wo\, obtained by using a new approach to this type of questions (joint pro
ject with Michele Pernice and Angelo Vistoli).\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Philip Engel (UGA)
DTSTART:20210707T140000Z
DTEND:20210707T150000Z
DTSTAMP:20260404T111414Z
UID:HUBerlinAG/28
DESCRIPTION:Title: Compact K3 moduli\nby Philip Engel (UGA) as part of Humbold
t Algebraic Geometry Seminar\n\n\nAbstract\nThis is joint work with Valery
Alexeev. By the Torelli theorem\, the moduli space $F_g$ of polarized K3
surfaces is the quotient of a 19-dimensional Hermitian symmetric space by
the action of an arithmetic group. In this capacity\, it admits a natural
class of "semitoroidal compactifications\," built from periodic tilings of
18-dimensional hyperbolic space. On the other hand\, $F_g$ also admits "s
table pair compactifications": Choosing canonically on any polarized K3 su
rface $X$ an ample divisor $R$\, there is a compact moduli space of "stabl
e pairs" containing the K3 pairs \n$(X\,R)$ as an opensubset.\n\nI will di
scuss two theorems in the talk: First\, there is a simple criterion on $R$
\, "recognizability"\, which implies that the normalization of a stable pa
ir compactification is semitoroidal. Second\, the sum of geometric genus z
ero curves in the polarization is recognizable. This gives rise to a modul
ar semitoroidal compactification for all $g$.\n
LOCATION:https://stable.researchseminars.org/talk/HUBerlinAG/28/
END:VEVENT
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