BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Marta Panizzut (Universität Osnabrück)
DTSTART;VALUE=DATE-TIME:20200424T120000Z
DTEND;VALUE=DATE-TIME:20200424T130000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/1
DESCRIPTION:Title: Tro
pical cubic surfaces and their lines\nby Marta Panizzut (Universität
Osnabrück) as part of Tropical Geometry in Zoom TGiZ\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/TGiZ/1/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jan Draisma (Universität Bern)
DTSTART;VALUE=DATE-TIME:20200424T131500Z
DTEND;VALUE=DATE-TIME:20200424T141500Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/2
DESCRIPTION:Title: Cat
alan-many morphisms to trees-Part I\nby Jan Draisma (Universität Bern
) as part of Tropical Geometry in Zoom TGiZ\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/TGiZ/2/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alejandro Vargas (Universität Bern)
DTSTART;VALUE=DATE-TIME:20200424T143000Z
DTEND;VALUE=DATE-TIME:20200424T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/3
DESCRIPTION:Title: Cat
alan-many morphisms to trees-Part II\nby Alejandro Vargas (Universitä
t Bern) as part of Tropical Geometry in Zoom TGiZ\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/TGiZ/3/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ben Smith (University of Manchester)
DTSTART;VALUE=DATE-TIME:20200529T120000Z
DTEND;VALUE=DATE-TIME:20200529T130000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/4
DESCRIPTION:Title: Fac
es of tropical polyhedra - cancelled\nby Ben Smith (University of Manc
hester) as part of Tropical Geometry in Zoom TGiZ\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/TGiZ/4/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Yue Ren (Swansea University)
DTSTART;VALUE=DATE-TIME:20200529T131500Z
DTEND;VALUE=DATE-TIME:20200529T141500Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/5
DESCRIPTION:Title: Tro
pical varieties of neural networks\nby Yue Ren (Swansea University) as
part of Tropical Geometry in Zoom TGiZ\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/TGiZ/5/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hannah Markwig (University of Tuebingen)
DTSTART;VALUE=DATE-TIME:20200529T143000Z
DTEND;VALUE=DATE-TIME:20200529T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/6
DESCRIPTION:Title: The
combinatorics and real lifting of tropical bitangents to plane quartics\nby Hannah Markwig (University of Tuebingen) as part of Tropical Geomet
ry in Zoom TGiZ\n\nAbstract: TBA\n
LOCATION:https://researchseminars.org/talk/TGiZ/6/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mark Gross (University of Cambridge)
DTSTART;VALUE=DATE-TIME:20200626T120000Z
DTEND;VALUE=DATE-TIME:20200626T130000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/7
DESCRIPTION:Title: Glu
ing log Gromov-Witten invariants\nby Mark Gross (University of Cambrid
ge) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nI will give a
progress report on joint work with Abramovich\, Chen and Siebert aiming t
o understand gluing formulae for log Gromov-Witten invariants\, generalizi
ng the Li/Ruan and Jun Li gluing formulas for relative Gromov-Witten invar
iants.\n
LOCATION:https://researchseminars.org/talk/TGiZ/7/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Luca Battistella (University of Heidelberg)
DTSTART;VALUE=DATE-TIME:20200626T131500Z
DTEND;VALUE=DATE-TIME:20200626T141500Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/8
DESCRIPTION:Title: A s
mooth compactification of genus two curves in projective space\nby Luc
a Battistella (University of Heidelberg) as part of Tropical Geometry in Z
oom TGiZ\n\n\nAbstract\nQuestions of enumerative geometry can often be tra
nslated into problems of intersection theory on a compact moduli space of
curves in projective space. Kontsevich's stable maps work extraordinarily
well when the curves are rational\, but in higher genus the burden of dege
nerate contributions is heavily felt\, as the moduli space acquires severa
l boundary components. The closure of the locus of maps with smooth source
curve is interesting but troublesome\, for its functor of points interpre
tation is most often unclear\; on the other hand\, after the work of Li--V
akil--Zinger and Ranganathan--Santos-Parker--Wise in genus one\, points in
the boundary correspond to maps that admit a nice factorisation through s
ome curve with Gorenstein singularities (morally\, contracting any higher
genus subcurve on which the map is constant). The question becomes how to
construct such a universal family of Gorenstein curves. In joint work with
F. Carocci\, we construct one such family in genus two over a logarithmic
modification of the space of admissible covers. I will focus on how tropi
cal geometry determines this logarithmic modification via tropical canonic
al divisors.\n
LOCATION:https://researchseminars.org/talk/TGiZ/8/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Kalina Mincheva (Yale University)
DTSTART;VALUE=DATE-TIME:20200626T143000Z
DTEND;VALUE=DATE-TIME:20200626T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/9
DESCRIPTION:Title: Pri
me tropical ideals\nby Kalina Mincheva (Yale University) as part of Tr
opical Geometry in Zoom TGiZ\n\n\nAbstract\nIn the recent years\, there ha
s been a lot of effort dedicated to developing the necessary tools for com
mutative algebra using different frameworks\, among which prime congruence
s\, tropical ideals\, tropical schemes. These approaches allows for the ex
ploration of the properties of tropicalized spaces without tying them up
to the original varieties and working with geometric structures inherently
defined in characteristic one (that is\, additively idempotent) semifield
s. In this talk we explore the relationship between tropical ideals and co
ngruences to conclude that the variety of a non-zero prime (tropical) idea
l is either empty or consists of a single point.\n
LOCATION:https://researchseminars.org/talk/TGiZ/9/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Xin Fang (Universität Köln)
DTSTART;VALUE=DATE-TIME:20201204T130000Z
DTEND;VALUE=DATE-TIME:20201204T140000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/10
DESCRIPTION:Title: Tr
opical flag varieties - a Lie theoretic approach\nby Xin Fang (Univers
ität Köln) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nIn t
his talk I will explain how to use Lie theory to describe the facets of a
maximal prime cone in a type A tropical complete flag variety. The face la
ttice of this cone encodes degeneration structures in Lie algebra\, quiver
Grassmannians and module categories of quivers. This talk bases on differ
ent joint works with (subsets of) G. Cerulli-Irelli\, E. Feigin\, G. Fouri
er\, M. Gorsky\, P. Littelmann\, I. Makhlin and M. Reineke\, as well as so
me work in progress.\n
LOCATION:https://researchseminars.org/talk/TGiZ/10/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Man-Wai Cheung (Harvard University)
DTSTART;VALUE=DATE-TIME:20201204T141500Z
DTEND;VALUE=DATE-TIME:20201204T151500Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/11
DESCRIPTION:Title: Po
lytopes\, wall crossings\, and cluster varieties\nby Man-Wai Cheung (H
arvard University) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract
\nCluster varieties are log Calabi-Yau varieties which are a union of alg
ebraic tori glued by birational "mutation" maps. Partial compactification
s of the varieties\, studied by Gross\, Hacking\, Keel\, and Kontsevich\,
generalize the polytope construction of toric varieties. However\, it is n
ot clear from the definitions how to characterize the polytopes giving com
pactifications of cluster varieties. We will show how to describe the comp
actifications easily by broken line convexity. As an application\, we will
see the non-integral vertex in the Newton Okounkov body of Gr(3\,6) comes
from broken line convexity. Further\, we will also see certain positive p
olytopes will give us hints about the Batyrev mirror in the cluster settin
g. The mutations of the polytopes will be related to the almost toric fibr
ation from the symplectic point of view. Finally\, we can see how to exten
d the idea of gluing of tori in Floer theory which then ended up with the
Family Floer Mirror for the del Pezzo surfaces of degree 5 and 6. The talk
will be based on a series of joint works with Bossinger\, Lin\, Magee\, N
ajera-Chavez\, and Vianna.\n
LOCATION:https://researchseminars.org/talk/TGiZ/11/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Lara Bossinger (UNAM Oaxaca)
DTSTART;VALUE=DATE-TIME:20201204T153000Z
DTEND;VALUE=DATE-TIME:20201204T163000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/12
DESCRIPTION:Title: Tr
opical geometry of Grassmannians and their cluster structure\nby Lara
Bossinger (UNAM Oaxaca) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbs
tract\nThe Grassmannain\, or more precisely its homogeneous coordinate rin
g with respect to the Plücker embedding\, was found to be a cluster algeb
ra by Scott in the early years of cluster theory. Since then\, this cluste
r structure was studied from many different perspectives by a number of ma
thematicians. As the whole subject of cluster algebras broadly speaking di
vides into two main perspectives\, algebraic and geometric\, so do the res
ults regarding Grassmannian. Geometrically\, the Grassmannian contains two
open subschemes that are dual cluster varieties.\n\nInterestingly\, we ca
n find tropical geometry in both directions: from the algebraic point of v
iew\, we discover relations between maximal cones in the tropicalization o
f the defining ideal (what Speyer and Sturmfels call the tropical Grassman
nian) and seeds of the cluster algebra. From the geometric point of view\,
due to work of Fock--Goncharov followed by work of Gross--Hacking--Keel--
Kontsevich we know that the scheme theoretic tropical points of the cluste
r varieties parametrize functions on the Grassmannian.\n\nIn this talk I a
im to explain the interaction of tropical geometry with the cluster struct
ure for the Grassmannian from the algebraic and the geometric point of vie
w.\n
LOCATION:https://researchseminars.org/talk/TGiZ/12/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alheydis Geiger (Universität Tübingen)
DTSTART;VALUE=DATE-TIME:20210122T130000Z
DTEND;VALUE=DATE-TIME:20210122T140000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/13
DESCRIPTION:Title: De
formations of bitangent classes of tropical quartic curves\nby Alheydi
s Geiger (Universität Tübingen) as part of Tropical Geometry in Zoom TGi
Z\n\n\nAbstract\nOver an algebraically closed field a smooth quartic curve
has 28 bitangent lines. Plücker proved that over the real numbers we hav
e either 4\, 8\, 16 or 28 real bitangents to a real quartic curve. A tropi
cal smooth quartic curve has exactly 7 bitangent classes which each lift e
ither 0 or 4 times over the real numbers. The shapes of these bitangent cl
asses have been classified by Markwig and Cueto in 2020\, who also determi
ned their real lifting conditions.\nHowever\, for a fixed unimodular trian
gulation different choices of coefficients imply different edge lengths of
the quartic and these can change the shape of the 7 bitangent classes and
might therefore influence their real lifting conditions.\nIn order to pro
ve Plückers Theorem about the number of real bitangents tropically\, we h
ave to study these deformations of the bitangent shapes. In a joint work w
ith Marta Panizzut we develope a polymake extension\, which computes the t
ropical bitangents. For this we determine two refinements of the secondary
fan: one for which the bitangent shapes in each cone stay constant and on
e for which the lifting conditions in each cone stay constant.\nThis is st
ill work in progress\, but there will be a small software demonstration.\n
LOCATION:https://researchseminars.org/talk/TGiZ/13/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matt Baker (Georgia Institute of Technology)
DTSTART;VALUE=DATE-TIME:20210122T141500Z
DTEND;VALUE=DATE-TIME:20210122T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/14
DESCRIPTION:Title: Pa
stures\, Polynomials\, and Matroids\nby Matt Baker (Georgia Institute
of Technology) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nA
pasture is\, roughly speaking\, a field in which addition is allowed to be
both multivalued and partially undefined. Pastures are natural objects fr
om the point of view of F_1 geometry and Lorscheid’s theory of ordered b
lueprints. I will describe a theorem about univariate polynomials over pas
tures which simultaneously generalizes Descartes’ Rule of Signs and the
theory of NewtonPolygons. Conjecturally\, there should be a similar pictur
e for several polynomials in several variables generalizing tropical inter
section theory. I will also describe a novel approach to the theory of mat
roid representations which revolves around a canonical universal pasture c
alled the “foundation” that one can attach to any matroid. This is jo
int work with Oliver Lorscheid.\n
LOCATION:https://researchseminars.org/talk/TGiZ/14/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Litt (University of Georgia)
DTSTART;VALUE=DATE-TIME:20210122T153000Z
DTEND;VALUE=DATE-TIME:20210122T163000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/15
DESCRIPTION:Title: Th
e tropical section conjecture\nby Daniel Litt (University of Georgia)
as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nGrothendieck's se
ction conjecture predicts that for a curve X of genus at least 2 over an a
rithmetically interesting field (say\, a number field or p-adic field)\, t
he étale fundamental group of X encodes all the information about rationa
l points on X. In this talk I will formulate a tropical analogue of the se
ction conjecture and explain how to use methods from low-dimensional topol
ogy and moduli theory to prove many cases of it. As a byproduct\, I'll con
struct many examples of curves for which the section conjecture is true\,
in interesting ways. For example\, I will explain how to prove the section
conjecture for the generic curve\, and for the generic curve with a ratio
nal divisor class\, as well as how to construct curves over p-adic fields
which satisfy the section conjecture for geometric reasons. This is joint
work with Wanlin Li\, Nick Salter\, and Padma Srinivasan.\n
LOCATION:https://researchseminars.org/talk/TGiZ/15/
END:VEVENT
BEGIN:VEVENT
SUMMARY:John Christian Ottem (University of Oslo)
DTSTART;VALUE=DATE-TIME:20210219T130000Z
DTEND;VALUE=DATE-TIME:20210219T140000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/16
DESCRIPTION:Title: Tr
opical degenerations and stable rationality\nby John Christian Ottem (
University of Oslo) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstrac
t\nI will explain how tropical degenerations and birational specialization
techniques can be used in rationality problems. In particular\, I will ap
ply these techniques to study quartic fivefolds and complete intersections
of a quadric and a cubic in P^6. This is joint work with Johannes Nicaise
.\n
LOCATION:https://researchseminars.org/talk/TGiZ/16/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Marco Pacini (Universidade Federal Fluminense)
DTSTART;VALUE=DATE-TIME:20210219T141500Z
DTEND;VALUE=DATE-TIME:20210219T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/17
DESCRIPTION:Title: A
universal tropical Jacobian over the moduli space of tropical curves\n
by Marco Pacini (Universidade Federal Fluminense) as part of Tropical Geom
etry in Zoom TGiZ\n\n\nAbstract\nWe introduce polystable divisors on a tro
pical curve\, which are the tropical analogue of polystable torsion-free r
ank-1 sheaves on a nodal curve. We show how to construct a universal tropi
cal Jacobian by means of polystable divisors on tropical curves. This spac
e can be seen as a tropical counterpart of Caporaso universal Picard schem
e. This is a joint work with Abreu\, Andria\, and Taboada.\n
LOCATION:https://researchseminars.org/talk/TGiZ/17/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Laura Escobar (Washington University in St. Louis)
DTSTART;VALUE=DATE-TIME:20210219T153000Z
DTEND;VALUE=DATE-TIME:20210219T163000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/18
DESCRIPTION:Title: Wa
ll-crossing and Newton-Okounkov bodies\nby Laura Escobar (Washington U
niversity in St. Louis) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbs
tract\nA Newton-Okounkov body is a convex set associated to a projective v
ariety\, equipped with a valuation. These bodies generalize the theory of
Newton polytopes. Work of Kaveh-Manon gives an explicit link between tropi
cal geometry and Newton-Okounkov bodies. In joint work with Megumi Harada
we use this link to describe a wall-crossing phenomenon for Newton-Okounko
v bodies.\n
LOCATION:https://researchseminars.org/talk/TGiZ/18/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Anthea Monod (Imperial College London)
DTSTART;VALUE=DATE-TIME:20210312T130000Z
DTEND;VALUE=DATE-TIME:20210312T140000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/19
DESCRIPTION:Title: Tr
opical geometry of phylogenetic tree spaces\nby Anthea Monod (Imperial
College London) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\n
The Billera-Holmes-Vogtmann (BHV) space is a well-studied moduli space of
phylogenetic trees that appears in many scientific disciplines\, including
computational biology\, computer vision\, combinatorics\, and category th
eory. Speyer and Sturmfels identify a homeomorphism between BHV space and
a version of the Grassmannian using tropical geometry\, endowing the space
of phylogenetic trees with a tropical structure\, which turns out to be a
dvantageous for computational studies. In this talk\, I will present the c
oincidence between BHV space and the tropical Grassmannian. I will then gi
ve an overview of some recent work I have done that studies the tropical G
rassmannian as a metric space and the practical implications of these resu
lts on probabilistic and statistical studies on real datasets of phylogene
tic trees.\n
LOCATION:https://researchseminars.org/talk/TGiZ/19/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Claudia He Yun (Brown University)
DTSTART;VALUE=DATE-TIME:20210312T141500Z
DTEND;VALUE=DATE-TIME:20210312T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/20
DESCRIPTION:Title: Th
e $S_n$-equivariant rational homology of the tropical moduli spaces $\\Del
ta_{2\,n}$\nby Claudia He Yun (Brown University) as part of Tropical G
eometry in Zoom TGiZ\n\n\nAbstract\nThe tropical moduli space $\\Delta_{g\
,n}$ is a topological space that parametrizes isomorphism classes of $n$-m
arked stable tropical curves of genus $g$ with total volume 1. Its reduced
rational homology has a natural structure of $S_n$-representations induce
d by permuting markings. In this talk\, we focus on $\\Delta_{2\,n}$ and c
ompute the characters of these $S_n$-representations for $n$ up to 8. We u
se the fact that $\\Delta_{2\,n}$ is a symmetric $\\Delta$-complex\, a con
cept introduced by Chan\, Glatius\, and Payne. The computation is done in
SageMath.\n
LOCATION:https://researchseminars.org/talk/TGiZ/20/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Daniel Corey (University of Wisconsin-Madison)
DTSTART;VALUE=DATE-TIME:20210312T153000Z
DTEND;VALUE=DATE-TIME:20210312T163000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/21
DESCRIPTION:Title: Th
e Ceresa class: tropical\, topological\, and algebraic\nby Daniel Core
y (University of Wisconsin-Madison) as part of Tropical Geometry in Zoom T
GiZ\n\n\nAbstract\nThe Ceresa cycle is an algebraic cycle attached to a sm
ooth algebraic curve. It is homologically trivial but not algebraically eq
uivalent to zero for a very general curve. In this sense\, it is one of th
e simplest algebraic cycles that goes ``beyond homology.'' The image of th
e Ceresa cycle under a certain cycle class map produces a class in étale
homology called the Ceresa class. We define the Ceresa class for a tropica
l curve and for a product of commuting Dehn twists on a topological surfac
e. We relate these to the Ceresa class of a smooth algebraic curve over C(
(t)). Our main result is that the Ceresa class in each of these settings i
s torsion. Nevertheless\, this class is readily computable\, frequently no
nzero\, and implies nontriviality of the Ceresa cycle when nonzero. This i
s joint work with Jordan Ellenberg and Wanlin Li.\n
LOCATION:https://researchseminars.org/talk/TGiZ/21/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jeremy Usatine (Brown University)
DTSTART;VALUE=DATE-TIME:20210430T131500Z
DTEND;VALUE=DATE-TIME:20210430T141500Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/22
DESCRIPTION:Title: St
ringy invariants and toric Artin stacks\nby Jeremy Usatine (Brown Univ
ersity) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nStringy H
odge numbers are certain generalizations\, to the singular setting\, of Ho
dge numbers. Unlike usual Hodge numbers\, stringy Hodge numbers are not de
fined as dimensions of cohomology groups. Nonetheless\, an open conjecture
of Batyrev's predicts that stringy Hodge numbers are nonnegative. In the
special case of varieties with only quotient singularities\, Yasuda proved
Batyrev's conjecture by showing that the stringy Hodge numbers are given
by orbifold cohomology. For more general singularities\, a similar cohomol
ogical interpretation remains elusive. I will discuss a conjectural framew
ork\, proven in the toric case\, that relates stringy Hodge numbers to mot
ivic integration for Artin stacks\, and I will explain how this framework
applies to the search for a cohomological interpretation for stringy Hodge
numbers. This talk is based on joint work with Matthew Satriano.\n
LOCATION:https://researchseminars.org/talk/TGiZ/22/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Shiyue Li (Brown University)
DTSTART;VALUE=DATE-TIME:20210430T143000Z
DTEND;VALUE=DATE-TIME:20210430T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/23
DESCRIPTION:Title: To
pology of tropical moduli spaces of weighted stable curves in higher genus
\nby Shiyue Li (Brown University) as part of Tropical Geometry in Zoom
TGiZ\n\n\nAbstract\nThe space of tropical weighted curves of genus g and
volume 1 is the dual complex of the divisor of singular curves in Hassett
’s moduli space of weighted stable genus g curves. One can derive plenty
of topological properties of the Hassett spaces by studying the topology
of these dual complexes. In this talk\, we show that the spaces of tropica
l weighted curves of genus g and volume 1 are simply-connected for all gen
us greater than zero and all rational weights\, under the framework of sym
metric Delta-complexes and via a result by Allcock-Corey-Payne 19. We also
calculate the Euler characteristics of these spaces and the top weight Eu
ler characteristics of the classical Hassett spaces in terms of the combin
atorics of the weights. I will also discuss some work in progress on a geo
metric group approach to simple connectivity of these spaces. This is join
t work with Siddarth Kannan\, Stefano Serpente\, and Claudia Yun.\n
LOCATION:https://researchseminars.org/talk/TGiZ/23/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Felipe Rincon (Queen Mary University of London)
DTSTART;VALUE=DATE-TIME:20210430T120000Z
DTEND;VALUE=DATE-TIME:20210430T130000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/24
DESCRIPTION:Title: Tr
opical Ideals\nby Felipe Rincon (Queen Mary University of London) as p
art of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nTropical ideals are i
deals in the tropical polynomial semiring in which any bounded-degree piec
e is “matroidal”. They were conceived as a sensible class of objects f
or developing algebraic foundations in tropical geometry. In this talk I w
ill introduce and motivate the notion of tropical ideals\, and I will disc
uss work studying some of their main properties and their possible associa
ted varieties.\n
LOCATION:https://researchseminars.org/talk/TGiZ/24/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Margarida Melo (University of Coimbra and University of Roma Tre)
DTSTART;VALUE=DATE-TIME:20210528T120000Z
DTEND;VALUE=DATE-TIME:20210528T130000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/25
DESCRIPTION:Title: On
the top weight cohomology of the moduli space of abelian varieties\nb
y Margarida Melo (University of Coimbra and University of Roma Tre) as par
t of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nThe moduli space of abe
lian varieties Ag admits well behaved toroidal compactifications whose dua
l complex can be given a tropical interpretation. Therefore\, one can use
the techniques recently developed by Chan-Galatius-Payne in order to under
stand part of the topology of Ag via tropical geometry. In this talk\, whi
ch is based in joint work with Madeleine Brandt\, Juliette Bruce\, Melody
Chan\, Gwyneth Moreland and Corey Wolfe\, I will explain how to use this s
etup\, and in particular computations in the perfect cone compactification
of Ag\, in order to describe its top weight cohomology for g up to 7.\n
LOCATION:https://researchseminars.org/talk/TGiZ/25/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jenia Tevelev (University of Massachusetts Amherst)
DTSTART;VALUE=DATE-TIME:20210528T143000Z
DTEND;VALUE=DATE-TIME:20210528T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/26
DESCRIPTION:Title: Co
mpactifications of moduli of points and lines in the (tropical) plane\
nby Jenia Tevelev (University of Massachusetts Amherst) as part of Tropica
l Geometry in Zoom TGiZ\n\n\nAbstract\nProjective duality identifies modul
i spaces of points and lines in the projective plane. The latter space adm
its Kapranov's Chow quotient compactification\, studied also by Lafforgue\
, Hacking-Keel-Tevelev\, and Alexeev\, which gives an example of a KSBA mo
duli space of stable surfaces: it carries a family of reducible degenerati
ons of the projective plane with "broken lines". From the tropical perspec
tive\, these degenerations are encoded in matroid decompositions and tropi
cal planes and their moduli space in the Dressian and the tropical Grasman
nian. In 1991\, Gerritzen and Piwek proposed a dual perspective\, a compac
t moduli space parametrizing reducible degenerations of the projective pla
ne with n smooth points. In a joint paper with Luca Schaffler\, we investi
gate the extension of projective duality to degenerations\, answering a qu
estion of Kapranov.\n
LOCATION:https://researchseminars.org/talk/TGiZ/26/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Baldur Sigurðsson (Vietnam Academy of Sciences and Technology)
DTSTART;VALUE=DATE-TIME:20210528T131500Z
DTEND;VALUE=DATE-TIME:20210528T141500Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/27
DESCRIPTION:Title: Lo
cal tropical Cartier divisors and the multiplicity\nby Baldur Sigurðs
son (Vietnam Academy of Sciences and Technology) as part of Tropical Geome
try in Zoom TGiZ\n\n\nAbstract\nWe consider the group of local tropical cy
cles in the local\ntropicalization of the local analytic ring of a toric v
ariety\, in\nparticular\, Cartier divisors defined by a function germ. We
see a\nformula for the multiplicity\, a result which is motivated by a cla
ssical\ntheorem of Wagreich for normal surface singularities.\n
LOCATION:https://researchseminars.org/talk/TGiZ/27/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hülya Argüz (Université de Versailles)
DTSTART;VALUE=DATE-TIME:20210625T120000Z
DTEND;VALUE=DATE-TIME:20210625T130000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/28
DESCRIPTION:Title: Tr
opical enumeration of real log curves in toric varieties and log Welsching
er invariants\nby Hülya Argüz (Université de Versailles) as part of
Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nWe give a new proof of a ce
ntral theorem in real enumerative geometry: the Mikhalkin correspondence t
heorem for Welschinger invariants. The proof goes through totally differen
t techniques as the original proof of Mikhalkin and is an adaptation to th
e real setting of the approach of Nishinou-Siebert to the complex correspo
ndence theorem. It uses log-geometry as a central tool. We will discuss ho
w this reinterpretation in terms of log-geometry may lead to new developme
nts\, as for example a real version of mirror symmetry. This is joint work
with Pierrick Bousseau.\n
LOCATION:https://researchseminars.org/talk/TGiZ/28/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Stefano Mereta (Swansea University)
DTSTART;VALUE=DATE-TIME:20210625T131500Z
DTEND;VALUE=DATE-TIME:20210625T141500Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/29
DESCRIPTION:Title: Tr
opical differential equations\nby Stefano Mereta (Swansea University)
as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nIn 2015 Dimitri G
rigoriev introduced a way to tropicalize differential equation with coeffi
cients in a power series ring and defined what a solution for such a tropi
calized equation should be. In 2016 Aroca\, Garay and Toghani proved a fun
damental theorem analogue to the fundamental theorem of tropical geometry
for power series over a trivially valued field. In this talk I will introd
uce the basic ideas moving then towards a functor of points approach to th
e subject by means of the recently developed tropical scheme theory\, as i
ntroduced by Giansiracusa and Giansiracusa\, looking at solutions to such
equations as morphisms between so-called pairs. I will also give a general
isation to power series ring with non-trivially valued coefficients and st
ate a colimit theorem along the lines of Payne's inverse limit theorem.\n
LOCATION:https://researchseminars.org/talk/TGiZ/29/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Eric Katz (Ohio State University)
DTSTART;VALUE=DATE-TIME:20210625T143000Z
DTEND;VALUE=DATE-TIME:20210625T153000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/30
DESCRIPTION:Title: Co
mbinatorial and p-adic iterated integrals\nby Eric Katz (Ohio State Un
iversity) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbstract\nThe cla
ssical operations of algebraic geometry often have combinatorial analogues
. We will discuss the combinatorial analogue of Chen’s iterated integral
s. These have a richer\, non-abelian structure than classical integrals. W
e will describe the tropical analogue of the unipotent Torelli theorem of
Hain and Pulte and make connections between iterated integrals and monodro
my with applications to p-adic integration.\n
LOCATION:https://researchseminars.org/talk/TGiZ/30/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mima Stanojkovski (RWTH Aachen University)
DTSTART;VALUE=DATE-TIME:20220121T130000Z
DTEND;VALUE=DATE-TIME:20220121T140000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/31
DESCRIPTION:Title: Or
ders and polytropes: matrices from valuations\nby Mima Stanojkovski (R
WTH Aachen University) as part of Tropical Geometry in Zoom TGiZ\n\n\nAbst
ract\nLet K be a discretely valued field with ring of integers R. To a d-b
y-d matrix M with integral coefficients one can associate an R-module\, in
K^{d x d}\, and a polytope\, in the Euclidean space of dimension d-1. We
will look at the interplay between these two objects\, from the point of v
iew of tropical geometry and building on work of Plesken and Zassenhaus. T
his is joint work with Y. El Maazouz\, M. A. Hahn\, G. Nebe\, and B. Sturm
fels.\n
LOCATION:https://researchseminars.org/talk/TGiZ/31/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ilya Tyomkin (Ben Gurioin University)
DTSTART;VALUE=DATE-TIME:20220121T141500Z
DTEND;VALUE=DATE-TIME:20220121T151500Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/32
DESCRIPTION:Title: Ap
plications of tropical geometry to irreducibility problems in algebraic ge
ometry\nby Ilya Tyomkin (Ben Gurioin University) as part of Tropical G
eometry in Zoom TGiZ\n\n\nAbstract\nIn my talk\, I will discuss a novel tr
opical approach to classical irreducibility problems of Severi varieties a
nd of Hurwitz schemes. I will explain how to prove such irreducibility res
ults by investigating the properties of tropicalizations of one-parameter
families of curves and of the induced maps to the tropical moduli space of
parametrized tropical curves. The talk is based on a series of joint work
s with Karl Christ and Xiang He.\n
LOCATION:https://researchseminars.org/talk/TGiZ/32/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Harry Richman (University of Washington)
DTSTART;VALUE=DATE-TIME:20220121T153000Z
DTEND;VALUE=DATE-TIME:20220121T163000Z
DTSTAMP;VALUE=DATE-TIME:20220124T064530Z
UID:TGiZ/33
DESCRIPTION:Title: Un
iform bounds for torsion packets on tropical curves\nby Harry Richman
(University of Washington) as part of Tropical Geometry in Zoom TGiZ\n\n\n
Abstract\nSay two points x\, y on an algebraic curve are in the same torsi
on packet if [x - y] is a torsion element of the Jacobian. In genus 0 and
1\, torsion packets have infinitely many points. In higher genus\, a theor
em of Raynaud states that all torsion packets are finite. It was long conj
ectured\, and only recently proven*\, that the size of a torsion packet is
bounded uniformly in terms of the genus of the underlying curve. We study
the tropical analogue of this construction for a metric graph. On a highe
r genus metric graph\, torsion packets are not always finite\, but they ar
e finite under an additional "genericity" assumption on the edge lengths.
Under this genericity assumption\, the torsion packets satisfy a uniform b
ound in terms of the genus of the underlying graph. (*by Kuehne and Looper
-Silverman-Wilmes in 2021)\n
LOCATION:https://researchseminars.org/talk/TGiZ/33/
END:VEVENT
END:VCALENDAR