Skip to content
Texas A&M University
Mathematics

Student/Postdoc Working Geometry Seminar

Fall 2020

 

Date:August 18, 2020
Time:10:00pm
Location:zoom
Speaker:J. Zuiddam, Courant
Title:Combinatorics, Tensors and Geometry
Abstract:There is a widely studied family of open problems in extremal combinatorics that can naturally be phrased in terms of tensors. This family includes the cap set problem and the sunflower problem. We present a geometric approach to this kind of problems, called Geometric Rank (Kopparty–Moshkovitz–Zuiddam, 2020). Geometric Rank is a natural extension of matrix rank to tensors that is different from previously known notions of rank for tensors. I will conclude with an informal exploration of a totally different potential approach to these problems that is in line with the celebrated Lovász theta function.

Date:October 28, 2020
Time:11:00pm
Location:zoom 
Speaker:JM Landsberg, TAMU
Title:A technical lemma of Friedland

Date:November 4, 2020
Time:11:00pm
Location:zoom
Speaker:R. Geng, TAMU
Title:The variety of commuting matrices and geometric rank

Date:November 6, 2020
Time:10:00pm
Location:zoom
Speaker:JM Landsberg, TAMU
Title:Mukai: moduli of rank 2 vector bundles on curves I

Date:November 11, 2020
Time:11:00pm
Location:zoom
Speaker:JM Landsberg, TAMU
Title:Mukai: moduli of rank 2 vector bundles on curves II

Date:November 13, 2020
Time:10:00pm
Location:zoom
Speaker:A. Huang, TAMU
Title:Def. theory, curves of genus 0 and 1.

Date:November 18, 2020
Time:11:00pm
Location:zoom
Speaker:JM Landsberg, TAMU
Title:The substitution method and linear sections of spaces of matrices of bounded rank

Date:November 23, 2020
Time:10:00pm
Location:zoom
Speaker:A. Harper, TAMU
Title:Def theory: the road to stacks

Date:November 25, 2020
Time:11:00am
Location:zoom
Speaker:F. Gesmundo, MPI Leipzig
Title:cubics with Hilbert function 1771

Date:November 29, 2020
Time:10:00am
Location:zoom
Speaker:A. Huang, TAMU
Title:Introduction to minimal free resolutions

Date:December 3, 2020
Time:10:45am
Location:zoom
Speaker:JM Landsberg, TAMU
Title:Introduction to Bott-Borel-Weil Thm.

Date:December 8, 2020
Time:10:00am
Location:zoom
Speaker:Chia-Yu Chang, TAMU
Title:Minimal components of the quot scheme I

Date:December 9, 2020
Time:09:00am
Location:zoom
Speaker:A. Pal, TAMU
Title:Tensors of minimal border rank

Date:December 16, 2020
Time:10:00am
Location:zoom
Speaker:Tomasz Mandzuik, U. Warsaw
Title: Limits of ideals of points in projective space
Abstract:The notion of the border rank of a homogeneous polynomial is related, by border apolarity, to ideals that are limits of ideals of points in general position in projective space. I will discuss some conditions for an ideal to be such a limit. For projective plane I will present a sufficient condition and for projective space of arbitrary dimension I will give a necessary condition.

Date:December 29, 2020
Time:10:00am
Location:zoom
Speaker:Amy Huang, TAMU
Title:Minimal Set of Generators of Ideals Defining Nilpotent Orbit Closures

Date:December 30, 2020
Time:10:00am
Location:zoom
Speaker:Arthur Bik, U. Bern
Title:Strength of polynomials via polynomial functors
Abstract:The strength of a homogeneous polynomial is a subadditive invariant determined by defining a polynomial to have strength 1 when it is reducible and nonzero. It has been defined by Ananyan and Hochster in their paper proving Stillman's conjecture and has appeared in various works since. The goal of this talk is prove that the set of homogeneous polynomials of degree d in n variables of strength at most r is not always Zariski-closed. The proof involves techniques from the geometry of polynomial functors, which we will define.