Algebra, Combinatorics, and Geometry Archives

Date Speakers
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>
4
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
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
University of Nebraska-Lincoln
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
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 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
Thursday, April 3, 2014 - 12:00
Divided difference operators for convex polytopes
Thursday, March 27, 2014 - 12:00
Factor critical graphs and irreducible decomposition of powers of edge ideals
Hoang Le Truong
Hanoi Institute of Math
Thursday, March 6, 2014 - 12:00
Some properties of the quasicategory of frames
Chris Kapulkin
Thursday, February 27, 2014 - 12:00
Toric Geometry in Coding Theory
Ivan Soprunov
Cleveland State
Thursday, February 20, 2014 - 12:00
On a notion of entropy in local algebra
Mahdi Majidi
CUNY
Thursday, February 13, 2014 - 12:00
Strategy for proving Joyal's conjecture
Chris Kapulkin
University of Pittsburgh
Thursday, February 6, 2014 - 12:00
Homotopy type theory and Joyal's conjecture
Chris Kapulkin
University of Pittsburgh
Thursday, November 21, 2013 - 12:00 to 13:00
A product formula for certain coefficients of Jack polynomials
Yusra Naqvi
Rutgers University
Thursday, November 7, 2013 - 12:00 to 13:00
Connected Hopf Algebras in Positive Characteristic
Xingting Wang
Washington University
Thursday, October 31, 2013 - 12:00
On a problem of Erdös and Rothschild on edges in triangles
Po-Shen Loh
Carnegie Mellon University
Thursday, October 24, 2013 - 12:00 to 13:00
Global and local Weyl modules for twisted current algebras
Bogdan Ion
University of Pittsburgh
Thursday, October 17, 2013 - 12:00 to 13:00
Skew plane partitions with non-homogeneous weights
Sevak Mkrtchyan
Carnegie Mellon University
Thursday, October 10, 2013 - 12:00 to 13:00
Introduction to Higher Categories II
Rina Anno
University of Pittsburgh
Thursday, October 3, 2013 - 12:00 to 13:00
Introduction to Higher Categories
Rina Anno
University of Pittsburgh
Thursday, September 26, 2013 - 12:00 to 13:00
Moduli stack of curves and principal bundles II
Thursday, September 19, 2013 - 12:00 to 13:00
Moduli stack of curves and principal bundles
University of Pittsburgh
Thursday, September 12, 2013 - 12:00 to 13:00
Tamagawa Numbers
University of Pittsburgh
Thursday, February 28, 2013 - 12:00 to 12:50
BGG reciprocity for current algebras
Bogdan Ion
University of Pittsburgh
Thursday, December 6, 2012 - 12:00 to 12:50
Design pairs
University of Pittsburgh
Thursday, November 29, 2012 - 12:00 to 12:45
Structure of braided tensor categories
Alexei Davydov
Ohio University
Thursday, November 15, 2012 - 12:00 to 13:00
The Combinatorial Commutative Algebra Of Conformal Blocks
Christopher Manon
George Mason University