Talk_id  Date  Speaker  Title 
8242

Monday 1/8 4:10 PM

David Hansen, Columbia University

Elliptic curves and padic Lfunctions
 Elliptic curves and padic Lfunctions
 01/08/2018
 4:10 PM  5:00 PM
 C304 Wells Hall
 David Hansen, Columbia University
I'll explain the notion of a padic Lfunction, try to
motivate why one might care about such a gadget, and give some history of their construction and applications. At the end of the talk I'll discuss a recent joint work with John Bergdall in which (among other things) we construct canonical padic Lfunctions associated with modular elliptic curves over totally real number fields.

8231

Tuesday 1/9 4:10 PM

Yoonsang Lee, Lawrence Berkeley National Laboratory

Uncertainty Quantification of Physicsconstrained Problems – Data Assimilation and Parameter Estimation
 Uncertainty Quantification of Physicsconstrained Problems – Data Assimilation and Parameter Estimation
 01/09/2018
 4:10 PM  5:00 PM
 C304 Wells Hall
 Yoonsang Lee, Lawrence Berkeley National Laboratory
Observation data along with mathematical models play a crucial role in improving prediction skills in science and engineering. In this talk we focus on the recent development of uncertainty quantification methods, data assimilation and parameter estimation, for Physicsconstrained problems that are often described by partial differential equations. We discuss the similarities shared by the two methods and their differences in mathematical and computational points of view and future research topics. As applications, numerical weather prediction for geophysical flows and parameter estimation of kinetic reaction rates in the hydrogenoxygen combustion are provided.

8230

Wednesday 1/10 4:10 PM

Preston Wake, UCLA

Quantifying congruences between Eisenstein series and cusp forms
 Quantifying congruences between Eisenstein series and cusp forms
 01/10/2018
 4:10 PM  5:00 PM
 C304 Wells Hall
 Preston Wake, UCLA
Consider the following two problems in algebraic number theory:
1. For which prime numbers p can we easily show that the Fermat equation x^p + y^p =z^p has no nontrivial integer solutions?
2. Given an elliptic curve E over the rational numbers, what can be said about the group of rational points of finite order on E?
These seem like very different problems, but, surprisingly, they share a common theme: they are both related to the existence of congruences between two types of modular forms, Eisenstein series and cusp forms. We will explain these examples, and discuss a new technique for giving quantitative information about these congruences (for example, counting the number of cusp forms congruent to an Eisenstein series). We will explain how this can give finer arithmetic information than simply knowing the existence of a congruence. This is joint work with Carl WangErickson.

8232

Friday 1/12 4:10 PM

John Calabrese, Rice University

From Hilbert's Nullstellensatz to quotient categories
 From Hilbert's Nullstellensatz to quotient categories
 01/12/2018
 4:10 PM  5:00 PM
 C304 Wells Hall
 John Calabrese, Rice University
A common theme in algebraic geometry is the interplay between algebra and geometry. In this talk I will discuss a few "reconstruction theorems", in which the algebra determines the geometry.

9248

Wednesday 1/17 4:10 PM

Tristan Collins, Harvard University

SasakiEinstein metrics and Kstability
 SasakiEinstein metrics and Kstability
 01/17/2018
 4:10 PM  5:00 PM
 C304 Wells Hall
 Tristan Collins, Harvard University
I will discuss the connection between SasakiEinstein metrics and algebraic geometry in the guise of Kstability. In particular, I will give a differential geometric perspective on Kstability which arises from the Sasakian view point, and use Kstability to find infinitely many nonisometric SasakiEinstein metrics on the 5sphere. This is joint work with G. Szekelyhidi.

9251

Wednesday 1/17 4:10 PM

Hitesh Gakhar, MSU

Dualities in Persistent (co)Homology
 Dualities in Persistent (co)Homology
 01/17/2018
 4:10 PM  5:00 PM
 C204A Wells Hall
 Hitesh Gakhar, MSU
For a filtered topological space, its persistent homology is a multiset of half open real intervals known as barcode. Each bar represents the lifespan of a homology class. A fundamental principle is that the length of such a bar determines the significance of the corresponding class. In 2011, V. de Silva et al studied the relationships between (persistent) absolute homology, absolute cohomology, relative homology and relative cohomology. This talk will be a theoretical overview of that study.

9253

Monday 1/22 4:10 PM

Joshua Ruiter, MSU

Infinite Galois Extensions
 Infinite Galois Extensions
 01/22/2018
 4:10 PM  5:00 PM
 C517 Wells Hall
 Joshua Ruiter, MSU
No abstract available.

7200

Monday 1/22 4:10 PM


Academic Integrity
 Academic Integrity
 01/22/2018
 4:10 PM  5:00 PM
 C109 Wells Hall

Dr. Robert Caldwell, MSU's Ombudsperson, will attend this meeting. This will be an opportunity to ask him questions regarding challenging scenarios many of us have encountered during exam proctoring, grading of tests and projects.

8235

Tuesday 1/23 1:15 PM

Elise Lockwood, Oregon State University

Investigating Subtleties of the Multiplication Principle
 Investigating Subtleties of the Multiplication Principle
 01/23/2018
 1:15 PM  2:45 PM
 252 EH
 Elise Lockwood, Oregon State University
Central to introductory probability, and a primary feature of most discrete mathematics courses, the Multiplication Principle is fundamental to combinatorics, underpinning many standard formulas and providing justification for counting strategies. Given its importance, the ways it is presented in textbooks are surprisingly varied. In this talk, I identify key elements of the principle and present a categorization of statement types that emerged from a textbook analysis. I also incorporate excerpts from a reinvention study that sheds light on how students reason through key elements of the principle. Findings from both the textbook analysis and the reinvention study reveal surprisingly subtle aspects of the multiplication principle that can be made concrete for students through carefully chosen examples. I conclude with a number of potential mathematical and pedagogical implications of the categorization.

9249

Tuesday 1/23 4:10 PM

Bruce Sagan, MSU

An Introduction to Stanley's Theory of PPartitions. I
 An Introduction to Stanley's Theory of PPartitions. I
 01/23/2018
 4:10 PM  5:00 PM
 C304 Wells Hall
 Bruce Sagan, MSU
Richard Stanley developed a powerful generalization of the theory of integer partitions where the parts of the partition are arranged on any labeled poset P. In this first lecture we will develop some intuition by computing the generating functions for various families of ordinary integer partitions. This will motivate Stanley's generalization which will be discussed in the second lecture. No background will be assumed.

9255

Wednesday 1/24 4:10 PM

Hitesh Gakhar, MSU

Dualities in Persistent (co)HomologyPart II
 Dualities in Persistent (co)HomologyPart II
 01/24/2018
 4:10 PM  5:00 PM
 C517 Wells Hall
 Hitesh Gakhar, MSU
For a filtered topological space, its persistent homology is a multiset of half open real intervals known as barcode. Each bar represents the lifespan of a homology class. A fundamental principle is that the length of such a bar determines the significance of the corresponding class. In 2011, V. de Silva et al studied the relationships between (persistent) absolute homology, absolute cohomology, relative homology and relative cohomology. This talk will be a theoretical overview of that study.

7231

Thursday 1/25 11:00 AM

Jonas Lührmann

Probabilistic scattering for the 4D energycritical defocusing nonlinear wave equation
 Probabilistic scattering for the 4D energycritical defocusing nonlinear wave equation
 01/25/2018
 11:00 AM  12:00 PM
 C304 Wells Hall
 Jonas Lührmann
We consider the Cauchy problem for the energycritical defocusing
nonlinear wave equation in four space dimensions. It is known that for
initial data at energy regularity, the solutions exist globally in time
and scatter to free waves. However, the problem is illposed for initial
data at supercritical regularity, i.e. for regularities below the
energy regularity.
In this talk we study the supercritical data regime for this Cauchy
problem from a probabilistic point of view, using a randomization
procedure that is based on a unitscale decomposition of frequency
space. We will present an almost sure global existence and scattering
result for randomized radially symmetric initial data of supercritical
regularity. This is the first almost sure scattering result for an
energycritical dispersive or hyperbolic equation for scaling
supercritical initial data.
The main novelties of our proof are the introduction of an approximate
Morawetz estimate to the random data setting and new large deviation
estimates for the free wave evolution of randomized radially symmetric data.
This is joint work with Ben Dodson and Dana Mendelson.

6187

Thursday 1/25 2:00 PM

Siqi He, Caltech

The Extended Bogomolny Equations and Teichmuller space
 The Extended Bogomolny Equations and Teichmuller space
 01/25/2018
 2:00 PM  3:00 PM
 C304 Wells Hall
 Siqi He, Caltech
We will discuss Witten’s gauge theory approach to Jones polynomial and Khovanov homology by counting solutions to some gauge theory equations with singular boundary conditions. When we reduce these equations to 3dimensional, we call them the extended Bogomolny equations. We will discuss a DonaldsonUlenbeckYau type correspondence of the moduli space of the singular solutions to the Extended Bogomolny equations and Teichmuller space. If time permits, we will also discuss the relationship of the singular solutions moduli space with higher Teichmuller theory. This is joint work with Rafe Mazzeo.

9256

Thursday 1/25 3:00 PM

Xiaochuan Yang, MSU

An invitation to large scale sojourn properties of Brownian motion
 An invitation to large scale sojourn properties of Brownian motion
 01/25/2018
 3:00 PM  3:50 PM
 C405 Wells Hall
 Xiaochuan Yang, MSU
For a one dimensional Brownian motion, we consider the sets of times where Brownian motion stays inside some moving boundaries. The boundaries considered are power functions with the power in [0, 1/2]. Since the usual scaling for Brownian motion at time t is square root of t, the sojourn sets we considered describe the recurrence of a Brownian motion around zero. We give large scale geometric properties of these sets using macroscopic dimensions introduced by Barlow and Taylor in the late 80's. The audience of 881/882 might find this talk interesting.

7201

Monday 1/29 4:10 PM

Bronlyn Wassink, Mathematics, MSU

QL Updates
 QL Updates
 01/29/2018
 4:10 PM  5:00 PM
 C109 Wells Hall
 Bronlyn Wassink, Mathematics, MSU
No abstract available.

7229

Wednesday 1/31 4:10 PM

Arie Israel, University of Texas at Austin

A new proof of the finiteness principle
 A new proof of the finiteness principle
 01/31/2018
 4:10 PM  5:00 PM
 C517 Wells Hall
 Arie Israel, University of Texas at Austin
The BrudnyiShvartsman finiteness principle is a foundational result in the study of Whitneytype extension problems. This result provides an answer to the following question: How can we tell whether there exists a Höldersmooth function that takes prescribed values on a given (arbitrary) subset of Euclidean space? In this talk I will describe new machinery for answering this question based on the notion of the “local complexity” of a set at a given position and scale. To complete the main induction argument we must prove that the complexity of an arbitrary set is bounded uniformly by an absolute constant. This is accomplished through an elementary lemma on the stabilization of the dynamics of a 1parameter family of nonisotropic dilations acting on the space of positivedefinite matrices. We conjecture an improvement to the constants in the stabilization lemma which would result in an improvement to the bestknown constants in the finiteness principle. This is joint work with A. FreiPearson and B. Klartag.

9247

Thursday 2/1 2:00 PM

Guillem Cazassus, Indiana University

TBA
 TBA
 02/01/2018
 2:00 PM  2:50 PM
 C304 Wells Hall
 Guillem Cazassus, Indiana University
No abstract available.

9254

Wednesday 2/7 4:10 PM

Vladimir Peller, Michigan State University

Absolute continuity of spectral shift
 Absolute continuity of spectral shift
 02/07/2018
 4:10 PM  5:00 PM
 C517 Wells Hall
 Vladimir Peller, Michigan State University
No abstract available.

8243

Thursday 2/8 2:00 PM

Boyu Zhang, Harvard University

Rectifiability and Minkowski bounds for the singular sets of multiplevalued harmonic spinors
 Rectifiability and Minkowski bounds for the singular sets of multiplevalued harmonic spinors
 02/08/2018
 2:00 PM  3:00 PM
 C304 Wells Hall
 Boyu Zhang, Harvard University
We prove that the singular set of a multiplevalued harmonic spinor on a 4manifold is 2rectifiable and has finite Minkowski content. This result improves a regularity result of Taubes in 2014. It implies more precise descriptions for the limit behavior of nonconvergent sequences of solutions to many important gaugetheoretic equations, such as the KapustinWitten equations, the VafaWitten equations, and the SeibergWitten equations with multiple spinors.

7214

Friday 2/16 4:10 PM

Ekaterina Rapinchuk, MSU

TBA
 TBA
 02/16/2018
 4:10 PM  5:00 PM
 C304 Wells Hall
 Ekaterina Rapinchuk, MSU
No abstract available.

9252

Wednesday 2/21 4:10 PM

Alexander Volberg, MSU

Fractional Laplacians on Hamming cube and its Poincar\'e inequalities
 Fractional Laplacians on Hamming cube and its Poincar\'e inequalities
 02/21/2018
 4:10 PM  5:00 PM
 C517 Wells Hall
 Alexander Volberg, MSU
No abstract available.

8236

Wednesday 2/28 1:45 PM

Jennifer LangerOsuna, Stanford University

Fostering productive and inclusive collaborative mathematics classrooms
 Fostering productive and inclusive collaborative mathematics classrooms
 02/28/2018
 1:45 PM  3:15 PM
 252 EH
 Jennifer LangerOsuna, Stanford University
Studentled group work is an increasingly common activity in K12 mathematics classrooms. Students are expected to debate ideas, justify conjectures, and come to consensus on reasonable approaches to solving problems. Yet several studies have shown that some students become unduly influential, while others' contributions are routinely marginalized. This talk pursues the question, how can collaborative mathematics classrooms foster both equity and productivity? To do so, this talk begins with an exploration of the role of authority relations during collaborative math activity, followed by new design research, in partnership with local schools, based on the results of earlier, exploratory work. The talk closes by contextualizing these projects in a broader body of work focused on examining classrooms designed to equitably engage students from diverse backgrounds in intellectually productive mathematical activity.

8237

Thursday 3/1 2:00 PM

Matthias Nagel, McMaster University, Canada

TBD
 TBD
 03/01/2018
 2:00 PM  3:00 PM
 C304 Wells Hall
 Matthias Nagel, McMaster University, Canada
No abstract available.

9245

Thursday 3/8 2:00 PM

No seminar

Spring Break
 Spring Break
 03/08/2018
 2:00 PM  3:00 PM
 C304 Wells Hall
 No seminar
No abstract available.

6188

Wednesday 3/21 4:10 PM


Yannick Sire
 Yannick Sire
 03/21/2018
 4:10 PM  5:00 PM
 C517 Wells Hall

No abstract available.

7202

Thursday 3/22 2:00 PM

Adam Lowrance, Vassar College

TBD
 TBD
 03/22/2018
 2:00 PM  3:00 PM
 C304 Wells Hall
 Adam Lowrance, Vassar College
No abstract available.

7215

Friday 3/23 4:10 PM

Kristen Hendricks, Mathematics, MSU

TBA
 TBA
 03/23/2018
 4:10 PM  5:00 PM
 C304 Wells Hall
 Kristen Hendricks, Mathematics, MSU
No abstract available.

7204

Monday 3/26 4:10 PM

Rita Gitik

A New Algorithm in Group Theory
 A New Algorithm in Group Theory
 03/26/2018
 4:10 PM  5:30 PM
 C304 Wells Hall
 Rita Gitik
We describe a new algorithm which determines if the intersection of a quasiconvex subgroup of a negatively curved group with any of its conjugates is infinite. The algorithm is based on the concepts of a coset graph and a weakly Nielsen generating set of a subgroup. We also give a new proof of decidability of a membership problem for quasiconvex subgroups of negatively curved groups.

9243

Thursday 3/29 2:00 PM

Ramanujan Santharoubane, University of Virginia

TBD
 TBD
 03/29/2018
 2:00 PM  3:00 PM
 C304 Wells Hall
 Ramanujan Santharoubane, University of Virginia
No abstract available.

9246

Thursday 4/5 2:00 PM

Juanita PinzonCalcedo, North Carolina State

TBA
 TBA
 04/05/2018
 2:00 PM  3:00 PM
 C304 Wells Hall
 Juanita PinzonCalcedo, North Carolina State
No abstract available.

9244

Thursday 4/12 2:00 PM

Adam Saltz, University of Georgia

TBA
 TBA
 04/12/2018
 2:00 PM  3:00 PM
 C304 Wells Hall
 Adam Saltz, University of Georgia
No abstract available.
