# Algebra, Combinatorics, and Geometry Archives

Date Speakers
Thursday, March 7, 2019 - 12:00 to 13:00
Multiplicity-Free Products of Schubert Divisors and an Application to Canonical Dimension
Rostislav Devyatov
University of Alberta
Thursday, February 14, 2019 - 12:00
Atiyah Class and Sheaf Counting on Local Calabi-Yau Fourfolds
Artan Sheshmani
Harvard University, Center for Mathematical Sciences and Applications
Thursday, December 6, 2018 - 12:00
Hyperplane Arrangements and Compactifying the Milnor Fiber
Jeremy Usatine
Yale University
Thursday, November 29, 2018 - 13:00 to 14:00
Toward double affine flag varieties and Grassmannians
Dinakar Muthiah
Kavli IPMU Tokyo
Thursday, November 29, 2018 - 12:00
Toric degenerations of the algebra of conformal blocks and compactifications of character varieties
Chris Manon
University of Kentucky
Thursday, November 15, 2018 - 12:00
Geometric approach to linear ODEs
Dima Arinkin
Thursday, November 8, 2018 - 12:00
A Verified ODE Solver and Smale's 14th Problem
Fabian Immler
Carnegie Mellon University
Thursday, October 25, 2018 - 12:00
Singular Fano Varietes
Alexander Borisov
Thursday, October 18, 2018 - 12:00
Cubical sets and higher category theory
Chris Kapulkin
University of Western Ontario
Thursday, October 11, 2018 - 12:00
On the statement of the classification of finite simple groups.
Thomas Hales
Thursday, October 4, 2018 - 12:00
Coherent Satake Functor
Roman Fedorov
Thursday, September 27, 2018 - 12:00
Character variety methods in 3-manifold topology
Jason DeBlois
Thursday, September 20, 2018 - 12:00
Cartan decomposition and K-orbits in spherical varieties
Kiumars Kaveh
Thursday, April 19, 2018 - 12:00
Counting cusp forms on Sp(4)
Mahdi Asgari
Oklahoma State University
Thursday, April 12, 2018 - 12:00
Virtual Gelfand-Zetlin Polytopes
Elise Villella
Thursday, April 5, 2018 - 12:00
The real projective spaces in homotopy type theory
Egbert Rijke
Carnegie Mellon University
Thursday, March 15, 2018 - 13:00
Combinatorics of canonical bases and cluster duality
Bea Schumann
Thursday, March 1, 2018 - 12:00
Algebraic structures from dependent type theory
Carnegie Mellon University
Thursday, February 22, 2018 - 12:00
Macdonald polynomial operators and coinvariant rings
James Haglund
University of Pennsylvania
Thursday, February 15, 2018 - 13:00
Toric vector bundles and buildings
Thursday, February 8, 2018 - 12:00
Koszul blowup algebras associated to three-dimensional Ferrers diagrams
Kuei-Nuan Lin
Penn State University
Tuesday, January 30, 2018 - 12:00
The Fourier Coefficients of a Minimal Parabolic Eisenstein Series on the Double Cover of GL(3) over Q.
Edmund Karasiewicz
University of California, Santa Cruz
Thursday, December 7, 2017 - 12:00
Computing with higher genus curves, abelian varieties and K3 surfaces
Thursday, November 30, 2017 - 12:00
Scaling-rotation statistics on symmetric positive definite matrices
Sungkyu Jung
University of Pittsburgh
Thursday, November 16, 2017 - 12:00
Consequences of the Uniform Position Principle for Spanning Lattice Polytopes
Johannes Hofscheier
McMaster University
Thursday, November 9, 2017 - 12:00
Mining ultraproduct proofs for bounds in polynomial rings
William Simmons
University of Pennsylvania
Thursday, November 2, 2017 - 13:00
Bott-Samelson varieties
Laura Escobar
UIUC
Thursday, October 26, 2017 - 12:00
Formal Abstracts in Mathematics
Thursday, October 19, 2017 - 12:00
Integrating over Hilbert schemes
Andras Szenes
Thursday, October 12, 2017 - 12:00
Convolution numbers
Thursday, October 5, 2017 - 12:00
Ranks of matrices with few distinct entries
Boris Bukh
Carnegie Mellon University
Thursday, September 28, 2017 - 13:00
Linear families of polytopes and a notion of anti-canonical class
Thursday, September 21, 2017 - 12:00
Formalized Spectral Sequences in Homotopy Type Theory II
Floris van Doorn
Carnegie Mellon University
Thursday, September 14, 2017 - 12:00
Formalized Spectral Sequences in Homotopy Type Theory I
Floris van Doorn
Carnegie Mellon University
Thursday, September 7, 2017 - 12:00
Toric degenerations of Projective Varieties
Thursday, April 13, 2017 - 12:00 to 13:00
Looking for Keller maps: a report on the hunt
Alexander Borisov
Thursday, April 6, 2017 - 12:00 to 13:00
Multiple zeta values and multiple Hurwitz-zeta values. Analytic and combinatorial aspects
Cezar Lupu
University of Pittsburgh
Thursday, March 16, 2017 - 12:00 to 13:00
Curves on algebraic surfaces and hyperbolic codes
Matt Stover
Temple University
Thursday, March 2, 2017 - 12:00
Congruence group actions on 2-affine braid groups
Bogdan Ion
Thursday, February 23, 2017 - 12:00
n-affine braid groups
Bogdan Ion
Thursday, February 9, 2017 - 12:00
Reinhardt conjecture as a problem in optimal control theory
Thomas Hales
Thursday, January 26, 2017 - 12:00
Motivic class of moduli of Higgs bundles, Part 2
Thursday, January 19, 2017 - 12:00
Motivic class of moduli of Higgs bundles
Thursday, November 10, 2016 - 12:00 to 13:00
A geometric perspective on Landau's theorem in function fields
Thursday, October 27, 2016 - 12:00
The fundamental lemma for Hecke algebras in large positive characteristic
Thursday, October 20, 2016 - 12:00
Quantitative Characterization of Finite Simple Groups and Related Topics
Wujie Shi
Chongqing University of Arts & Sciences and Suzhou University
Thursday, October 13, 2016 - 12:00
Geometry of planar surfaces and exceptional fillings
Neil Hoffman
Oklahoma State University
Thursday, October 6, 2016 - 12:00
Optimal partition problems
Marco Caroccia
Carnegie Mellon University
Tuesday, September 20, 2016 - 12:00
Real, p-adic, and motivic (oscillatory) integrals and applications
Raf Cluckers
CRNS (Le Centre national de la recherche scientifique), France
Thursday, September 15, 2016 - 12:00
Algebraic tori and counting p-adic fields
Thursday, September 8, 2016 - 12:00
The optimal packing of congruent regular pentagons in the plane
Thursday, August 25, 2016 - 12:00
Configurations of Spheres
Woden Kusner
Graz University of Technology
Thursday, April 21, 2016 - 12:00
The representation problem for ternary quadratic polynomials.
Anna Haensch
Duquesne University
Thursday, April 14, 2016 - 12:00
Cubical sets with symmetries and the homotopy coherent nerve functor
Chris Kapulkin
Thursday, March 31, 2016 - 12:00
Fisher information and the discrete Laplacian, with applications
Thursday, March 24, 2016 - 12:00
Tropical geometry and Grobner theory for spherical homogeneous spaces
Thursday, March 17, 2016 - 12:00
Generalized Riemannian geometry
Thursday, March 3, 2016 - 12:00 to 13:00
Noncommutative Symmetric Groups in Noncommutative Projective Algebraic Geometry
Xingting Wang
Temple University
Thursday, February 25, 2016 - 12:00
Springer W-action and equivariant cohomology
Thursday, January 14, 2016 - 13:00 to 14:00
Affine Lie algebras, quantum K-theory, and combinatorics
Cristian Lenart
SUNY Albany
Tuesday, December 15, 2015 - 12:00
Congruent relations, cyclotomic expansion and volume conjecture for SU(n) invariants
Shengmao Zhu
Zhejiang University
Thursday, December 10, 2015 - 12:00 to 13:00
Systoles of arithmetic hyperbolic manifolds
Ben McReynolds
Purdue
Thursday, December 3, 2015 - 12:00
Bergman kernel and invariant theory
Thursday, November 19, 2015 - 12:00
Special complex structures and their deformation properties: Hodge numbers and stability
Sheng Rao
University of California, Los Angeles
Thursday, November 12, 2015 - 12:00
Commutative Character Sheaves
Thursday, November 5, 2015 - 12:00
Hilbert schemes and parking functions
Andrei Neguț
MIT
Thursday, October 22, 2015 - 12:00
The representation theory of sphere packings
Thursday, October 15, 2015 - 12:00
The Kudla Program
Zavosh Amir-Khosravi
Thursday, October 8, 2015 - 12:00
Toric degenerations and symplectic geometry of projective varieties II
Thursday, October 1, 2015 - 12:00
Toric degenerations and symplectic geometry of projective varieties
Thursday, October 1, 2015 - 12:00
Toric degenerations and symplectic geometry of projective varieties
<p>The purpose of this talk is to discuss some recent general results about symplectic geometry of smooth projective varieties using toric degenerations (motivated by commutative algebra). The main result is the following: Let X be a smooth n-dimensional complex projective variety embedded in a projective space and equipped with a Kahler structure induced from a Fubini-Study Kahler form. We show that for any \epsilon&gt;0 the manifold X has an open subset U (in the usual topology) such that vol(X \ U) &lt; \epsilon and moreover U is symplectomorphic to the algebraic torus (\C^*)^n equipped with a toric Kahler form. The proof is based on construction of a toric degeneration of X. As applications we obtain lower bounds on the Gromov width of X. Moreover, we show that X has a full symplectic ball packing by d balls of capacity 1 where d is the degree of X.</p>
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Thursday, September 24, 2015 - 12:00
On the Schwartz space of a smooth semi-algebraic stack
Yiannis Sakellaridis
Rutgers University
Thursday, September 24, 2015 - 12:00
On the Schwartz space of a smooth semi-algebraic stack
Yiannis Sakellaridis
Rutgers University
Thursday, September 10, 2015 - 12:00
Computing p-adic families of modular symbols
Thursday, April 2, 2015 - 12:00
Introduction to factorization homology
Chris Kapulkin
University of Western Ontario
Thursday, April 2, 2015 - 12:00
Introduction to factorization homology
Chris Kapulkin
University of Western Ontario
Thursday, March 26, 2015 - 12:00
Tautological ring of moduli spaces of curves
Thursday, March 19, 2015 - 12:00
Macdonald conjectures for multivariate hypergeometric functions
Siddhartha Sahi
Rutgers University, New Brunswick
Thursday, March 19, 2015 - 12:00
Macdonald conjectures for multivariate hypergeometric functions
Siddhartha Sahi
Rutgers University, New Brunswick
Tuesday, March 17, 2015 - 12:00
Generalized Whittaker functionals for real reductive groups
Siddhartha Sahi
Rutgers University, New Brunswick
Thursday, March 5, 2015 - 12:00
Stability conditions for sub-quotients of category O
Vinoth Nandakumar
MIT
Wednesday, February 25, 2015 - 12:00
Springer W-action and equivariant cohomology
Thursday, February 19, 2015 - 12:00
The 290-Theorem and Representing Numbers by Quadratic Forms
Jonathan Hanke
Thursday, February 5, 2015 - 12:00
The maximum injectivity radius of hyperbolic 2-orbifolds
Federica Fanoni
University of Fribourg
Thursday, January 29, 2015 - 12:00
Serre's tensor construction and moduli of abelian schemes - Part 2
Zavosh Amir-Khosravi
4
Thursday, January 29, 2015 - 12:00
Serre's tensor construction and moduli of abelian schemes - Part 2
Zavosh Amir-Khosravi
Thursday, January 22, 2015 - 12:00
Serre's tensor construction and moduli of abelian schemes
Zavosh Amir-Khosravi
Thursday, January 15, 2015 - 12:00
Tropical geometry
Thursday, December 4, 2014 - 12:00
Genus of complete intersections and Ehrhart-Macdonald reciprocity for convex polytopes 2
University of Pittsburgh
Thursday, November 20, 2014 - 12:00
An affine quantum cohomology ring and periodic Toda lattice
Leonardo Mihalcea
Virginia Tech
Thursday, November 13, 2014 - 12:00
Genus of complete intersections and Ehrhart-Macdonald reciprocity for convex polytopes 1
University of Pittsburgh
Thursday, November 13, 2014 - 12:00
Genus of complete intersections and Ehrhart-Macdonald reciprocity for convex polytopes 1
<p>I will describe the beautiful Ehrhart-Macdonald theorem which connects number of integral points in a convex polytope $\Delta$ and the number of integral points strictly inside $\Delta$. I will discuss the relation with Serre duality in algebraic geometry and finally show how one can use this to compute genus of complete intersections in smooth toric varieties. In a recent work (in progress, joint with A. G. Khovanskii) we generalize this to the so-called spherical varieties of any connected reductive group G. I will try to explain most of the necessary background.</p>
University of Pittsburgh
Tuesday, November 4, 2014 - 11:00
Newton-type diagrams for singular flags and counting number of solutions of polynomials
Pinaki Mondal
Weitzman Institute of Science
Thursday, October 30, 2014 - 12:00
Hadean numbers - exploring the underworld of reduced plane algebraic curves
Brian Harbourne
Thursday, October 23, 2014 - 12:00
The socle, lattice of normal subgroups, and faithful irreducible characters 2
University of Pittsburgh
Thursday, October 16, 2014 - 12:00
The socle, lattice of normal subgroups, and faithful irreducible characters 1
<p>A study of the Mobius function on the lattice of normal subgroups yields information of the number of conjugacy classes required to generate a finite group. It is shown how this number is reflected in the character table. A result of Geschutz states that faithful irreducible characters exist if and only if the socle is generated by a sole conjugacy class. By studying all faithful irreducible characters, generalizations of this result are presented. Faithful irreducible characters are shown to be orthogonal modulo the socle of the group. This leads, in particular, to information on the structure constants of the socle.</p>
University of Pittsburgh
Thursday, October 16, 2014 - 12:00
The socle, lattice of normal subgroups, and faithful irreducible characters 1
University of Pittsburgh
Thursday, October 9, 2014 - 12:00
Homotopy and homology of moduli spaces of elliptic curves 2
University of Pittsburgh
Thursday, October 2, 2014 - 12:00
Homotopy and homology of moduli spaces of elliptic curves 1
University of Pittsburgh
Thursday, April 17, 2014 - 12:00
Rankin-Selberg Theory of L-functions
Mahdi Asgari