# Events for 02/13/2019 from all calendars

## Geometry Seminar

**Time:** 10:30AM - 11:30AM

**Location:** BLOC 628

**Speaker:** Jose Burgos Gil, ICMAT, Madrid

**Title:** *Arithmetic of Toric Varieties, Lecture 3*

**Abstract:** See lecture 1 for series abstract.

## Number Theory Seminar

**Time:** 1:45PM - 2:45PM

**Location:** BLOC 624

**Speaker:** Maurice Rojas, Texas A&M University

**Title:** *Faster point counting over prime power rings and pseudo-random generators*

**Abstract:**

We discuss a recent advance enabling a simple, randomized polynomial-time algorithm to count the roots of any polynomial in one variable over the prime power ring Z/(p^k). (The best previous general algorithms were exponential.) We also show how this implies a fast algorithm for computing certain Igusa zeta functions. These zeta functions, along with several other families of zeta functions, have been proposed as a method for generating one-way functions and pseudo-random generators by Anshel, Goldfeld, and Zuniga-Galindo. We'll review the latter connections as well.

This is joint work with Yuyu Zhu, and build upon earlier joint work with Qi Cheng, Shuhong Gao, Leann Kopp, Natalie Randall, and Daqing Wan.

**URL:** *Link*

## Noncommutative Geometry Seminar

**Time:** 2:00PM - 3:00PM

**Location:** BLOC 628

**Speaker:** Clément Dell'Aiera, University of Hawaii

**Title:** *Decomposition complexity, a dynamical approach*

**Abstract:** Finite Decomposition Complexity was introduced by E. Guentner, R. Tessera and G. Yu as a generalization of finite asymptotic dimension. We will investigate how it can be suitably defined for topological actions of discrete groups (more generally topological groupoids), and present some applications in Operator Algebras and K-theory, e.g. one can obtain the Künneth formula for the uniform Roe algebra of some groups which are not coarsely embeddable into Hilbert space. Other applications include the Baum-Connes conjecture.

## Groups and Dynamics Seminar

**Time:** 3:00PM - 4:00PM

**Location:** BLOC 220

**Speaker:** Sarah Witherspoon, Texas A&M

**Title:** *Koszul algebras*

**Abstract:** We will give several equivalent definitions of Koszul algebras, with examples.

## AMUSE

**Time:** 6:00PM - 7:00PM

**Location:** BLOC 220

**Speaker:** Vahid Attari, PhD Student, Department of Materials Science & Engineering, TAMU

**Title:** *Phase-field modeling of microstructure for designing high-performance industrial alloys*

**Abstract:** Phase-field approach is a relatively young interdisciplinary technique still being developed to predict the complex chain of chemistry, structure, processing, and property in materials. To make reliable predictions of materials response during service conditions, we should realize that the properties of a material and its integrity are controlled by the structure of the alloy in Micron to Nano scales. In this talk, I review the mathematical foundations of the phase-field approach and give examples of the calculated microstructures from real world alloys. These include the calculated microstructures for (1) the solder materials in electronic 3D Integrated Circuits (3D ICs), (2) thermoelectric materials for electricity generation through low-grid waste heat sources, potentially used in space exploration applications, (3) ultra-hard coating materials and many other examples. Phase-field approach can be very expensive and supercomputing knowledge is a plus. The goal of my talk is to introduce you to the interdisciplinary field of phase-field modeling where excellent mathematical and engineering skills are required to help design novel materials for novel applications.