# Seminars & Events for 2017-2018

February 8, 2017
3:00pm - 4:00pm
##### Michael Harrison
###### Algebraic Topology Seminar
Speaker: Michael Harrison , Lehigh University
Location:
Fine Hall 110
February 15, 2017
3:00am - 4:00pm
##### TBA-Dan Isaksen
###### Algebraic Topology Seminar
Speaker: Dan Isaksen, Wayne State University
Location:
Fine Hall 110
March 29, 2017
3:00pm - 3:00pm
##### TBA-Eric Bahuaude
###### Special Seminar in Geometric Analysis
Speaker: Eric Bahuaude, Seattle University
September 12, 2017
3:00pm - 4:00pm
##### The Tutte embedding of the mated-CRT map converges to Liouville quantum gravity
###### Topics in Probability

We discuss the proof that the Tutte embeddings (a.k.a. harmonic or barycentric embeddings) of certain random planar maps converge to $\gamma$-Liouville quantum gravity ($\gamma$-LQG). Specifically, we treat mated-CRT maps, which are discretized matings of correlated continuum random trees, and $\gamma$ ranges from $0$ to $2$ as one varies the correlation parameter.

Speaker: Ewain Gwynne , MIT
Location:
Fine Hall 110
September 13, 2017
3:00pm - 4:00pm
##### A conformally invariant gap theorem in Yang-Mills theory
###### Differential Geometry & Geometric Analysis Seminar

We show a sharp conformally invariant gap theorem for Yang-Mills connections in dimension 4 by exploiting an associated Yamabe-type problem. This is joint work with Jeffrey Streets (UC Irvine) and Matthew Gursky (University of Notre Dame).

Speaker: Casey Kelleher, Princeton University
Location:
Fine Hall 314
September 14, 2017
12:30pm - 1:30pm
##### Unknotting 2-dimensional spheres in S^4

In this talk, we discuss an interesting link between topology in dimensions 3 and 4. Scharlemann (1985) proved that a 2-sphere embedded in S^4 with 4 critical heights (an analog of bridge number from knot theory in S^3) is the boundary of a smooth 3-ball.

Speaker: Maggie Miller, Princeton University
Location:
Fine Hall 110
September 14, 2017
4:30pm - 5:30pm
##### 2^∞-Selmer groups, 2^∞-class groups, and Goldfeld's conjecture
###### Princeton University/IAS Number Theory Seminar

Take E/Q to be an elliptic curve with full rational 2-torsion (satisfying some extra technical assumptions). In this talk, we will show that 100% of the quadratic twists of E have rank less than two, thus proving that the BSD conjecture implies Goldfeld's conjecture in these families.

Speaker: Alex Smith , Harvard University
Location:
IAS Room S-101
September 18, 2017
3:00pm - 4:30pm
##### Regularity and blow up in models of fluid mechanics
###### Analysis Seminar

I will discuss a family of modified SQG equations that varies between 2D Euler and SQG with patch-like initial data defined on half-plane. The family is modulated by a parameter that sets the degree of the kernel in the Biot-Savart law. The main result I would like to describe is the phase transition in the behavior of solutions that happens right beyond the 2D Euler case.

Speaker: Alexander Kiselev, Duke University
Location:
Fine Hall 314
September 18, 2017
4:00pm - 5:00pm
##### Walking within growing domains: recurrence versus transience
###### PACM/Applied Mathematics Colloquium

When is simple random walk on growing in time d-dimensional domains recurrent? For domain growth which is independent of the walk, we review recent progress and related universality conjectures about a sharp recurrence versus transience criterion in terms of the growth rate.

Speaker: Amir Dembo, Stanford University
Location:
Fine Hall 214
September 19, 2017
2:30pm - 3:30pm
##### Towards de-mystification of deep learning: function space analysis of the representation layers
###### PACM IDeAS

PLEASE NOTE DIFFERENT DAY (TUESDAY).  We propose a function space approach to Representation Learning [1] and the analysis of the representation layers in deep learning architectures. We show how to compute a `weak-type'  Besov smoothness index that quantifies the geometry of the clustering in the feature space.

Speaker: Shai Dekel, Tel Aviv University
Location:
Fine Hall 224
September 19, 2017
4:30pm - 5:30pm
##### A variety with non-finitely generated automorphism group
###### Algebraic Geometry Seminar

If X is a projective variety, then Aut(X)/Aut^0(X) is a countable group, but little is known about what groups can occur. I will construct a projective variety for which this group is not finitely generated, and discuss how the construction can adapted to give an example of a complex projective variety with infinitely many non-isomorphic real forms.

Speaker: John Lesieutre , Penn State
Location:
Fine Hall 322
September 20, 2017
3:00pm - 4:00pm
##### Local Universality of Random Functions
###### Probability Seminar

In this talk, we discuss local universality results for a general class of random functions that includes random trigonometric polynomials and random orthogonal polynomials. We then apply these results to obtain estimates for the number of real roots and prove, in some cases, that this number satisfies the Central Limit Theorem. This is joint work with Van Vu.

Speaker: Oanh Nguyen, Princeton University
Location:
Fine Hall 214
September 20, 2017
3:00pm - 4:00pm
##### Almost Rigidity of the Positive Mass Theorem
###### Differential Geometry & Geometric Analysis Seminar

The Positive Mass Theorem states that an asymptotically flat Riemannian manifold, $M^3$, with nonegative Scalar curvature has nonnegative ADM mass, $m_{ADM}(M)\ge 0$, and if the ADM mass is 0 then we have rigidity: the manifold is isometric to Euclidean space.  It has long been known that if one has a sequence of such manifolds $M^3_j$ with $m_{ADM}(M_j) \to 0$ then $M_j$ need not converge smoo

Speaker: Christina Sormani , CUNY
Location:
Fine Hall 314
September 21, 2017
3:00pm - 4:30pm
##### Stability results in graphs of given circumference
###### Discrete Mathematics Seminar

In this talk we will discuss some Turan-type results on graphs with a given circumference. Let W_{n,k,c} be the graph obtained from a clique K_{c-k+1} by adding n-(c-k+1) isolated vertices each joined to the same k vertices of the clique, and let f(n,k,c)=e(W_{n,k,c}).

Speaker: Jie Ma , University of Science and Technology of China
Location:
Fine Hall 224
September 21, 2017
4:30pm - 5:30pm
##### Cohomology of p-adic Stein spaces
###### Princeton University/IAS Number Theory Seminar

I will discuss a comparison theorem that allows us to recover p-adic (pro-)etale cohomology of p-adic Stein spaces with semistable reduction over local rings of mixed characteristic from complexes of differential forms. To illustrate possible applications, I will show how it allows us to compute cohomology of Drinfeld half-space in any dimension and  of its coverings in dimension one.

Speaker: Wieslawa Niziol , ENS Lyon
Location:
Fine Hall 214
September 21, 2017
4:30pm - 5:30pm
##### Global well-posedness for the 2D Muskat problem
###### Analysis of Fluids and Related Topics

The Muskat problem was originally introduced by Muskat in order to model the interface between water and oil in tar sands. In general, it describes the interface between two incompressible, immiscible fluids of different constant densities in a porous media.

Speaker: Stephen Cameron, University of Chicago
Location:
Fine Hall 322
September 21, 2017
4:30pm - 5:30pm
##### Bordered Heegaard Floer homology with torus boundary via immersed curves
###### Topology Seminar

I will describe a geometric interpretation of bordered Heegaard Floer invariants in the case of a manifold M with torus boundary. In particular these invariants, originally defined as homotopy classes of modules over a particular algebra, can be described as collections of decorated immersed curves in the boundary of M.

Speaker: Jonathan Hanselman, Princeton University
Location:
Fine Hall 314
September 25, 2017
3:00pm - 4:00pm
##### Dynamical relativistic liquid bodies
###### Analysis Seminar

In this talk, I will discuss a new approach to establishing the well-posedness of the relativistic Euler equations for liquid bodies in vacuum. The approach is based on a wave formulation of the relativistic Euler equations  that consists of a system of non-linear wave equations in divergence form together with a combination of acoustic and Dirichlet boundary conditions.

Speaker: Todd Oliynyk , Monash University
Location:
Fine Hall 314
September 25, 2017
4:00pm - 5:00pm
##### TBA - Amir Ali Ahmadi
###### PACM/Applied Mathematics Colloquium
Speaker: Amir Ali Ahmadi, Princeton University
Location:
Fine Hall 214
September 26, 2017
3:00pm - 4:00pm
##### Convergence of finite-range weakly asymmetric exclusion processes on a circle
###### Topics in Probability

We consider spatially periodic growth models built from weakly asymmetric exclusion processes with finite-range jumps and rates depending locally on configuration. We prove that at a large scale and after renormalization these processes converge to the Hopf-Cole solution of the KPZ equation driven by Gaussian space-time white noise.

Speaker: Konstantin Matetski , University of Toronto
Location:
Fine Hall 110