## Colloquium

##### Thursday, December 1, 2016 at 3:30p.m. in Vincent Hall 16

#####
**Tom Church**
(*Stanford*)

**Abstract:**Representation theory over Z is famously intractable, but "representation stability" provides a way to get around these difficulties, at least asymptotically, by enlarging our groups until they behave more like commutative rings. Moreover, it turns out that important questions in topology/number theory/representation theory/... correspond to asking whether familiar algebraic properties hold for these "rings". I'll explain how these connections work; describe what we know and don't know; and give a wide sampling of applications in different fields where this has led to concrete results. No knowledge of representation theory will be required -- indeed, that's sort of the whole point!

### Monday, 28 November 2016

#### Reading Seminar on Automorphic Forms

*Reading Seminar for Automorphic Forms*at 9:00a.m. in VinH 570

Please send an email to wanxx123@umn.edu for more information.

#### Student Number Theory Seminar

*Student Number Theory Seminar*at 12:20p.m. in VinH 313

Please send an email to grodz007@umn.edu for more information.

#### Probability Seminar

*Singular Stochastic PDEs - How do they arise and what do they mean?*at 2:30p.m. in VinH 570

**Hao Shen**(

*Columbia*)

Systems with random fluctuations are ubiquitous in the real world. Stochastic PDEs are default models for these random systems, just as PDEs are default models ...
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Please send an email to arnab@umn.edu for more information.

#### Topology Seminar

*Topology Seminar*at 2:30p.m. in VinH 311

Please send an email to cwesterl@umn.edu for more information.

#### Automorphic Forms and Number Theory

*Automorphic Forms and Number Theory [will not meet]*at 3:35p.m. in VinH 311/364

Please send an email to garrett@umn.edu for more information.

#### Cockburn's Seminar

*Approximating Functions with Singularities*at 3:35p.m. in 213 Vincent Hall

Title: Approximating Functions with Singularities

### Tuesday, 29 November 2016

#### Climate Seminar

*Climate Change Seminar*at 11:15a.m. in VinH 570

Please send an email to mcgehee@umn.edu for more information.

#### Differential Geometry / Symplectic Topology Seminar

*Differential Geometry and Symplectic Topology seminar*at 1:25p.m. in Vinh 570

Please send an email to lixxx248@umn.edu for more information.

#### IMA Data Science Lab Seminar

*Joakim Anden: Three-Dimensional Covariance Estimation from Noisy Tomographic Projections*at 2:30p.m. in Lind 305

**Joakim Anden**(

*Princeton University*)

Particles imaged in cryo-electron microscopy (cryo-EM) often do not exist in a single molecular structure but exhibit significant structural variability. To determine the biological function ...
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Please send an email to lerman@umn.edu for more information.

### Wednesday, 30 November 2016

#### Student PDE Seminar

*Fundamental Solutions for 2nd Order Elliptic Operators*at 11:10a.m. in Vincent Hall 20

**Jonathan Hill**

Fundamental solutions are central objects in the study of linear differential equations. I will review some ways that they are useful and some of their ...
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Please send an email to poggi008@umn.edu for more information.

#### PDE Seminar

*The singular free boundary in the Signorini problem*at 3:30p.m. in VinH 113

**Mariana Smit Vega Garcia**(

*University of Washington*)

In this talk I will overview the Signorini problem for a divergence form elliptic operator with Lipschitz coefficients, and I will describe a few methods ...
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Please send an email to capop@umn.edu for more information.

### Thursday, 1 December 2016

#### IMA Annual Program

*Aaron Welters: Toward a Theory of Broadband Absorption Suppression in Magnetic Composites*at 11:00a.m. in Lind 305

**Aaron Welters**(

*Florida Institute of Technology*)

A major problem with magnetic materials in application is they naturally have high losses in a wide frequency range of interest (e.g., Faraday rotation using ...
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#### Geometric Analysis Learning Seminar

*Ricci flow on manifolds with positive isotropic curvature*at 11:10a.m. in VinH 570

**Fei He**

Please send an email to hexxx221@umn.edu for more information.

#### Commutative Algebra Seminar

*Commutative Algebra Seminar*at 11:15a.m. in 140 NCCE

Please send an email to cbekesc@math.umn.edu for more information.

#### Math Club Seminar

*Math Club*at 12:20p.m. in VinH 570

Please send an email to mathclub.umn@gmail.com for more information.

#### Math Physics Seminar

*Math Physics Seminar*at 12:20p.m. in Vincent Hall 215

**Tomoki Ohsawa**(

*UT Dallas*)

It is well known that both classical and quantum mechanical systems are described as Hamiltonian systems: finite-dimensional one for the former, and infinite-dimensional for the ...
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Please send an email to karl0163@umn.edu for more information.

#### PDE Seminar

*New Interactions between Analysis and Number Theory*at 1:25p.m. in VinH 570

**Stefan Steinerberger**(

*Yale University*)

I will discuss three different topics that connect classical analysis with number theory in a new and unexpected way (remarks and comments are very much ...
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Please send an email to capop@umn.edu for more information.

#### Differential Geometry / Symplectic Topology Seminar

*Differential Geometry and Symplectic Topology seminar - No Seminar*at 1:25p.m. in Vinh 570

Please send an email to lixxx248@umn.edu for more information.

#### SIAM Student Reading Group Seminar

#### PDE Seminar

*Large Time Behaviour in Fisher-KPP Type Equations*at 2:30p.m. in VinH 570

**Jean-Michel Roquejoffre**(

*University of Toulouse*)

The Fisher-KPP (Kolmogorov, Petrovskii, Piskunov) equation in one space variable is one of the simplest looking reaction-diffusion equations. The solution starting from a Heaviside initial ...
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Please send an email to capop@umn.edu for more information.

#### Colloquium

*Asymptotic representation theory over Z*at 3:30p.m. in Vincent Hall 16

**Tom Church**(

*Stanford*)

Representation theory over Z is famously intractable, but "representation stability" provides a way to get around these difficulties, at least asymptotically, by enlarging our groups ...
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more
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Please send an email to cad@umn.edu for more information.

#### Student Combinatorics Seminar

*Student Combinatorics Seminar*at 4:40p.m. in VinH 213

Please send an email to douvr001@umn.edu for more information.

### Friday, 2 December 2016

#### IMA Industrial Problems Seminar

*Jesse Berwald, Ryan Siskind: High-dimensional Retail*at 1:25p.m. in Lind 305

**Jesse Berwald, Ryan Siskind**(

*Target Corporation,*)

For many problems encountered in industry a mathematical solution lands the user in a high dimensional space. Often the space is sparse even given terabytes ...
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#### Combinatorics Seminar

*Exotic cluster algebras*at 2:30p.m. in Vinh 570

**Idan Eisner**(

*University of Haifa*)

Cluster algebras are commutative rings with a distinguished set of generators that are grouped into overlapping finite sets of the same cardinality. Among many other ...
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Please send an email to tscrimsh@umn.edu for more information.

#### Probability Seminar

*Probability Semianr - No Seminar*at 2:30p.m. in VinH 207

Please send an email to arnab@umn.edu for more information.

#### IMA Data Science Lab Seminar

*Stefan Steinerberger: Elliptic PDEs and Diffusion: Short Proofs by Counting Particles and Applications*at 2:30p.m. in Lind 305

**Stefan Steinerberger**

We describe a simple trick in the study of elliptic PDEs: introduce time and interpret the solution of the elliptic pde as a fixed point ...
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Please send an email to lerman@umn.edu for more information.

#### Applied and Computational Math Colloquium

*Applied and Computational Math Colloquium*at 2:30p.m. in Vincent Hall 2

Please send an email to jyfoo@umn.edu for more information.

#### Lie Theory Seminar

*The orbit method via deformations of singular symplectic varieties*at 3:30p.m. in Vincent Hall 301

**Ivan Loseu**(

*Northeastern University*)

One of the cornerstones of the infinite dimensional Lie representation theory is Kirillov's Orbit method (1961). It says that the irreducible unitary representations of a ...
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Please send an email to dhjiang@math.umn.edu for more information.

#### MCFAM Seminar

*Industry Competition, Profitability and Stock Returns*at 5:30p.m. in Vincent Hall 16

Speaker: Yao Deng Affiliation: UMN Carlson PhD in Finance Candidate/MCFAM MFM Alumnus Bio: Yao Deng is currently a third year finance PhD student at University ...
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Please send an email to rdixon@math.umn.edu for more information.