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:20260422T225923Z
UID:HUBerlinAG/1
DESCRIPTION:Title: Birational geometry of blow-ups of the projective space along linear su
bspaces and automorphisms of Kummer surfaces\nby Zhuang He (HU Berlin)
as part of Humboldt Algebraic Geometry Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Thomas Krämer (HU Berlin)
DTSTART:20201111T140000Z
DTEND:20201111T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/2
DESCRIPTION:Title: Semicontinuity of Gauss maps and the Schottky problem\nby Thomas Kr
ämer (HU Berlin) as part of Humboldt Algebraic Geometry Seminar\n\nAbstra
ct: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Michael Kemeny (Wisconsin)
DTSTART:20201118T150000Z
DTEND:20201118T160000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/3
DESCRIPTION:Title: Minimal rank generators for syzygies of canonical curves\nby Michae
l Kemeny (Wisconsin) as part of Humboldt Algebraic Geometry Seminar\n\nAbs
tract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Nicola Tarasca (Virginia)
DTSTART:20201125T140000Z
DTEND:20201125T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/4
DESCRIPTION:Title: Motivic classes of degeneracy loci and pointed Brill-Noether varieties<
/a>\nby Nicola Tarasca (Virginia) as part of Humboldt Algebraic Geometry S
eminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gaetan Borot (HU Berlin)
DTSTART:20201202T140000Z
DTEND:20201202T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/5
DESCRIPTION:Title: ELSV and topological recursion for double Hurwitz numbers\nby Gaeta
n Borot (HU Berlin) as part of Humboldt Algebraic Geometry Seminar\n\nAbst
ract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lawrence Ein
DTSTART:20201209T150000Z
DTEND:20201209T160000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/6
DESCRIPTION:Title: Singularities and syzygies of secant varieties of curves\nby Lawren
ce Ein as part of Humboldt Algebraic Geometry Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yohan Brunebarbe
DTSTART:20201216T140000Z
DTEND:20201216T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/7
DESCRIPTION:Title: Increasing hyperbolicity of varieties supporting a variation of Hodge s
tructures with level structures\nby Yohan Brunebarbe as part of Humbol
dt Algebraic Geometry Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ignacio Barros (Paris-Saclay)
DTSTART:20210113T140000Z
DTEND:20210113T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/8
DESCRIPTION:Title: On the irrationality of moduli spaces of K3 surfaces\nby Ignacio Ba
rros (Paris-Saclay) as part of Humboldt Algebraic Geometry Seminar\n\nAbst
ract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ruijie Yang (Stony Brook)
DTSTART:20210113T151500Z
DTEND:20210113T161500Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/9
DESCRIPTION:Title: Decomposition theorem for semisimple local systems\nby Ruijie Yang
(Stony Brook) as part of Humboldt Algebraic Geometry Seminar\n\nAbstract:
TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Frederik Benirschke (Stony Brook)
DTSTART:20210120T140000Z
DTEND:20210120T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/10
DESCRIPTION:Title: Boundary of linear subvarieties\nby Frederik Benirschke (Stony Bro
ok) as part of Humboldt Algebraic Geometry Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yeuk Hay Joshua Lam (Harvard)
DTSTART:20210120T151500Z
DTEND:20210120T161500Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/11
DESCRIPTION:Title: Calabi-Yau varieties and Shimura varieties\nby Yeuk Hay Joshua Lam
(Harvard) as part of Humboldt Algebraic Geometry Seminar\n\nAbstract: TBA
\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dawei Chen (Boston College)
DTSTART:20210210T140000Z
DTEND:20210210T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/12
DESCRIPTION:Title: Connected components of the space of k-differentials\nby Dawei Che
n (Boston College) as part of Humboldt Algebraic Geometry Seminar\n\nAbstr
act: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Claire Voisin (College de France)
DTSTART:20210217T140000Z
DTEND:20210217T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/13
DESCRIPTION:Title: Schiffer variations of hypersurfaces and the generic Torelli theorem\nby Claire Voisin (College de France) as part of Humboldt Algebraic Geo
metry Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Carl Lian (HU Berlin)
DTSTART:20210303T140000Z
DTEND:20210303T150000Z
DTSTAMP:20260422T225923Z
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\nAbstract: TBA
\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Giacomo Mezzedimi (Hannover)
DTSTART:20210127T140000Z
DTEND:20210127T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/15
DESCRIPTION:Title: The Kodaira dimension of some moduli spaces of elliptic K3 surfaces\nby Giacomo Mezzedimi (Hannover) as part of Humboldt Algebraic Geometry
Seminar\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Leonardo Lerer (Paris-Saclay)
DTSTART:20210106T140000Z
DTEND:20210106T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/16
DESCRIPTION:Title: Cohomology jump loci on singular varieties\nby Leonardo Lerer (Par
is-Saclay) as part of Humboldt Algebraic Geometry Seminar\n\nAbstract: TBA
\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrey Soldatenkov (HU Berlin)
DTSTART:20210414T140000Z
DTEND:20210414T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/17
DESCRIPTION:Title: Holonomy of the Obata connection on hypercomplex manifolds\nby And
rey Soldatenkov (HU Berlin) as part of Humboldt Algebraic Geometry Seminar
\n\n\nAbstract\nThe algebra of quaternions has been a focus of attention i
n many branches of mathematics ever since its introduction by Hamilton. On
e may think that quaternions form a noncommutative finite extension of the
field of complex numbers. For a geometer\, it is natural to wonder if the
re exists a suitable notion of a quaternionic variety\, analogous to a com
plex algebraic variety. I will try to give an introduction to this circle
of ideas\, explain how one can approach quaternionic (or hypercomplex) geo
metry and what natural problems arise in this context. One important notio
n in hypercomplex geometry is the Obata connection\, the unique torsion-fr
ee connection that preserves the action of the quaternions. I will present
some results on the study of its holonomy.\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alessandro Verra (Universita Roma Tre)
DTSTART:20210421T140000Z
DTEND:20210421T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/18
DESCRIPTION:Title: The Igusa quartic and the Prym map\nby Alessandro Verra (Universit
a Roma Tre) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbstract\n
The Igusa\, or the Castelnuovo-Richmond quartic is a famous hypersurface o
f the complex projective 4-space known for its ubiquity in algebraic geome
try. It is related to the Prym map $P$ in genus 6. As is well known the m
ap $P$ has degree 27 and dominates the moduli space of 5-dimensional princ
ipally polarized abelian varieties. Other maps with the same monodromy ar
e associated to $P$ and reflect related configurations. Among these these
of particular importance is the map $J: D \\rightarrow A_5$\, with fibre t
he configuration of double sixes of lines of the cubic surface. We descri
be $J$ geometrically\, showing that it is birationally equivalent to the p
eriod map for the moduli space $D$ of 30-nodal quartic threefolds\, cutti
ng twice a quadratic section of the Igusa quartic.\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hannah Larson (Stanford University)
DTSTART:20210428T150000Z
DTEND:20210428T160000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/19
DESCRIPTION:Title: The rational Chow rings of $M_7$\, $M_8$\, and $M_9$\nby Hannah La
rson (Stanford University) as part of Humboldt Algebraic Geometry Seminar\
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 r
ing is tautological (generated by certain natural classes known as kappa c
lasses). In recent joint work with Sam Canning\, we prove that the rationa
l Chow ring of $M_g$ is tautological for $g = 7\, 8\, 9$\, thereby determi
ning the Chow rings by work of Faber. In this talk\, I will give an overvi
ew of our approach\, with particular focus on the locus of tetragonal curv
es (special curves admitting a degree 4 map to $\\mathbb{P}^1$).\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mina Aganagic (University of California Berkeley)
DTSTART:20210512T150000Z
DTEND:20210512T160000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/20
DESCRIPTION:Title: Khovanov Homology from Mirror Symmetry\nby Mina Aganagic (Universi
ty of California Berkeley) as part of Humboldt Algebraic Geometry Seminar\
n\n\nAbstract\nKhovanov showed\, more than 20 years ago\, that there is a
deeper theory underlying the Jones polynomial. The “knot categorificatio
n problem” is to find a uniform description of this theory\, for all gau
ge groups\, which originates from physics\, or geometry. I will describe t
wo solutions to this problem\, which I recently discovered\, related by a
version of two dimensional (homological) mirror symmetry. The theories are
significantly more efficient than the algebraic descriptions mathematicia
ns have found\, even in the Khovanov homology case.\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rahul Pandharipande (ETH Zürich)
DTSTART:20210526T140000Z
DTEND:20210526T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/21
DESCRIPTION:Title: Tevelev degrees and Hurwitz moduli spaces\nby Rahul Pandharipande
(ETH Zürich) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbstract
\nI will explain various numerical and cohomological questions related to
Hurwitz moduli spaces (including older results with Faber on tautological
classes and newer calculations with Cela and Schmitt on Tevelev degrees).\
n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Salim Tayou (Harvard University)
DTSTART:20210519T150000Z
DTEND:20210519T160000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/22
DESCRIPTION:Title: Equidistribution of Hodge loci\nby Salim Tayou (Harvard University
) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbstract\nGiven a po
larized variation of Hodge structures\, it is a classical result that 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 codimens
ion Noether-Lefschetz loci\, equidistribution of Hecke translates of a cur
ve in $A_g$ and equidistribution of some families of CM points in Shimura
varieties. The results of this talk are joint work with Nicolas Tholozan.\
n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:François Greer (Stony Brook University)
DTSTART:20210505T140000Z
DTEND:20210505T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/23
DESCRIPTION:Title: A tale of two Severi curves\nby François Greer (Stony Brook Unive
rsity) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbstract\nLet $
(S\,L)$ be a general polarized K3 surface of degree $2g-2$. A general memb
er of the linear system $|L|\\simeq \\mathbb P^g$ is a smooth curve of gen
us $g$. For $0\\leq h\\leq g$\, define the Severi variety $V_h(S\,L)\\subs
et |L|$ to be the locus of curves with geometric genus $\\leq h$. As expec
ted\, $V_h(S\,L)$ has dimension $h$. We consider the case $h=1$\, where th
e Severi variety is a (singular) curve. Our first result is that the geome
tric genus of $V_1(S\,L)$ goes to infinity with $g$\; we give a lower boun
d $\\sim e^{c\\sqrt{g}}$. Next we consider the analogous question for Seve
ri curves of a rational elliptic surface\, and give a polynomial upper bou
nd instead. Modular forms play a central role in both arguments.\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Gerard Freixas i Montplet (IMJ-PRG)
DTSTART:20210616T140000Z
DTEND:20210616T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/24
DESCRIPTION:Title: Complex Chern-Simons and the first tautological class\nby Gerard F
reixas i Montplet (IMJ-PRG) as part of Humboldt Algebraic Geometry Seminar
\n\n\nAbstract\nIn this talk I will propose a construction of the complex
Chern-Simons line bundle\, in the context of a family of compact Riemann s
urfaces and a relative moduli space of flat vector bundles on it. The cons
truction is inspired by Deligne's functorial interpretation of Arakelov ge
ometry\, 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\, and non-a
belian Hodge theory is a fundamental tool in the approach. We will discuss
some properties of the complex Chern-Simons line bundle\, and an applicat
ion to a differential geometric incarnation of the first tautological clas
s on the moduli space of curves. This is joint work with Dennis Eriksson a
nd Richard Wentworth.\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:David Holmes (University of Leiden)
DTSTART:20210602T140000Z
DTEND:20210602T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/26
DESCRIPTION:Title: The double-double ramification cycle\nby David Holmes (University
of Leiden) as part of Humboldt Algebraic Geometry Seminar\n\n\nAbstract\nA
basic question in the geometry of Riemann surfaces is to decide when a gi
ven divisor of degree 0 is the divisor of a rational function (is principa
l). In the 19th century Abel and Jacobi gave a beautiful solution: one wri
tes the divisor as the boundary of a 1-cycle\, and the divisor is principa
l if and only if every holomorphic differential integrates to zero against
this cycle. From a modern perspective it is natural to allow the curve an
d divisor to vary in a family\, perhaps allowing the curve to degenerate t
o a singular (stable) curve so that the corresponding moduli space is comp
act. The double ramification cycle can then be seen as a virtual fundament
al class of the locus in the moduli space of curves over which our divisor
becomes principal. We will focus on two basic questions: where does the d
ouble ramification cycle naturally live\, and what happens when we interse
ct two double ramification cycles? We will see why (logarithmically) blowi
ng up the moduli space can make life easier. This is joint work with Rosa
Schwarz\, building on earlier joint work with Aaron Pixton and Johannes Sc
hmitt.\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Andrea di Lorenzo (HU Berlin)
DTSTART:20210609T140000Z
DTEND:20210609T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/27
DESCRIPTION:Title: The integral Chow ring of the stack of stable 1-pointed curves of genu
s two\nby Andrea di Lorenzo (HU Berlin) as part of Humboldt Algebraic
Geometry Seminar\n\n\nAbstract\nModuli stacks of curves play a prominent r
ole in algebraic geometry. In particular\, their rational Chow rings have
been the subject of intensive research in the last forty years\, since Mum
ford first investigated the subject. There is also a well defined notion o
f integral Chow ring for these stacks: this is more refined\, but also muc
h harder to compute. In this talk I will present the computation of the in
tegral Chow ring of the stack of stable 1-pointed curves of genus two\, ob
tained by using a new approach to this type of questions (joint project wi
th Michele Pernice and Angelo Vistoli).\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Philip Engel (UGA)
DTSTART:20210707T140000Z
DTEND:20210707T150000Z
DTSTAMP:20260422T225923Z
UID:HUBerlinAG/28
DESCRIPTION:Title: Compact K3 moduli\nby Philip Engel (UGA) as part of Humboldt Algeb
raic Geometry Seminar\n\n\nAbstract\nThis is joint work with Valery Alexee
v. By the Torelli theorem\, the moduli space $F_g$ of polarized K3 surface
s is the quotient of a 19-dimensional Hermitian symmetric space by the act
ion of an arithmetic group. In this capacity\, it admits a natural class o
f "semitoroidal compactifications\," built from periodic tilings of 18-dim
ensional hyperbolic space. On the other hand\, $F_g$ also admits "stable p
air compactifications": Choosing canonically on any polarized K3 surface $
X$ an ample divisor $R$\, there is a compact moduli space of "stable pairs
" containing the K3 pairs \n$(X\,R)$ as an opensubset.\n\nI will discuss t
wo theorems in the talk: First\, there is a simple criterion on $R$\, "rec
ognizability"\, which implies that the normalization of a stable pair comp
actification is semitoroidal. Second\, the sum of geometric genus zero cur
ves in the polarization is recognizable. This gives rise to a modular semi
toroidal compactification for all $g$.\n
LOCATION:https://researchseminars.org/talk/HUBerlinAG/28/
END:VEVENT
END:VCALENDAR