# Seminars & Events for 2014-2015

December 11, 2014
4:30pm - 6:00pm
##### On the stability of Prandtl boundary layer expansions of Navier-Stokes in the inviscid limit
###### Analysis of Fluids and Related Topics

I will present two recent results concerning the stability of boundary layer asymptotic expansions of solutions of Navier-Stokes with small viscosity. First, we show that the linearization around an arbitrary stationary shear flow (other than the Couette flow) admits an unstable eigenfunction with small wave number, when viscosity is sufficiently small.

Speaker: Toan Nguyen , Penn State
Location:
Fine Hall 322
December 12, 2014
1:30pm - 2:30pm
##### On normal crossings symplectic divisors
###### Joint PU/IAS Symplectic Geometry Seminar

I will describe purely symplectic notions of normal crossings divisor and configuration. They are compatible with the existence of the desired auxiliary almost Kahler structures, provided existence" is suitably interpreted. These notions lead to a multifold version of Gompf's symplectic sum construction.

Speaker: Aleksey Zinger , Stony Brook
Location:
Fine Hall 322
December 12, 2014
3:00pm - 4:00pm
##### Sign of Green's function of Paneitz operator and the Q curvature equations
###### Differential Geometry & Geometric Analysis Seminar

I will review some recent works with Paul on the fourth order Paneitz operators and Q curvature equations. Among other things, we will discuss the positivity of Green's function of Paneitz operator and its applications to finding constant Q curvature metrics by variational methods.

Speaker: Fengbo Hang, NYU
Location:
Fine Hall 314
December 15, 2014
9:00am - 5:00pm
##### Analysis, Spectra, and Number Theory: A Conference in Honor of Peter Sarnak on his 61th Birthday
###### Special Events and Conferences

The conference will focus on analytic number theory, with emphasis on its many relationships with analysis and spectral theory. Topics to be highlighted include arithmetic quantum chaos, analysis of families of L-functions, arithmetic statistics, and connections with ergodic theory. It will include a problem session to suggest future directions for the field.

Speaker: ,
Location:
McDonnell Hall A02
December 16, 2014
2:00pm - 3:30pm
##### TBA - Griffiths
###### Algebraic Geometry Seminar
Speaker: Philip Griffiths , IAS
Location:
IAS Room S-101
December 17, 2014
11:15am - 12:15pm
##### TBA - Doran
###### Algebraic Geometry Seminar

Please note special day and time.

Speaker: Charles Doran , University of Alberta
Location:
December 19, 2014
1:30pm - 2:30pm
##### TBA - McGibbon
###### Joint PU/IAS Symplectic Geometry Seminar
Speaker: Jason McGibbon, University of Massachusetts
Location:
IAS Room S-101
January 16, 2015
3:00pm - 4:00pm
##### Global existence for fully nonlinear stochastic hyperbolic equations : the Nash-Moser approach
###### Differential Geometry & Geometric Analysis Seminar

In 1979, Klainerman proved the first global existence result for fully nonlinear hyperbolic equations using Nash-Moser's method. The result was a breakthrough in the field.

Speaker: Mamadou Sango, University of Pretoria
Location:
Fine Hall 314
January 20, 2015
3:00pm - 4:00pm
##### Minimal surfaces in H2xR
###### Differential Geometry & Geometric Analysis Seminar

PLEASE NOTE SPECIAL DAY AND LOCATION:  Talk #1.  In the classical theory of minimal surfaces of the Euclidean space, the better known ones are those with finite total curvature.

Location:
Fine Hall 224
January 20, 2015
4:15pm - 5:15pm
##### A positive mass theorem for asymptotically flat manifolds with a noncompact boundary and an application to a Yamabe-type flow
###### Differential Geometry & Geometric Analysis Seminar

PLEASE NOTE SPECIAL DAY AND LOCATION:  Talk #2.  First I will discuss a positive mass theorem for noncompact manifolds with boundary and ends asymptotic to the Euclidean half-space.

Speaker: Sergio Almaraz, Universidade Federal Fluminense
Location:
Fine Hall 224
January 22, 2015
4:00pm - 5:00pm
##### Mean curvature flow without singularities
###### Differential Geometry & Geometric Analysis Seminar

Please note special day, time and location.  We study graphical mean curvature flow of complete solutions defined on subsets of Euclidean space. We obtain smooth long time existence. The projections of the evolving graphs also solve mean curvature flow.

Speaker: Mariel Saez, Universidad Catolica de Chile
Location:
Fine Hall 214
January 29, 2015
4:30pm - 5:30pm
##### Endoscopy theory for symplectic and orthogonal similitude groups
###### Princeton University/IAS Number Theory Seminar

The endoscopy theory provides a large class of examples of Langlands functoriality, and it also plays an important role in the classification of automorphic forms. The central part of this theory are some conjectural identities of Harish-Chandra characters between a reductive group and its endoscopic groups.

Speaker: Bin Xu, IAS
Location:
IAS Room S-101
January 30, 2015
1:30pm - 2:30pm
##### Symplectic forms in algebraic geometry
###### Joint PU/IAS Symplectic Geometry Seminar

Imposing the existence of a holomorphic symplectic form on a projective algebraic variety is a very strong condition. After describing various instances of this phenomenon (among which is the fact that so few examples are known!), I will focus on the specific topic of maps from projective varieties admitting a holomorphic symplectic form.

Speaker: Giulia Saccà, IAS
Location:
IAS Room S-101
February 2, 2015
3:15pm - 4:30pm
##### A model for studying double exponential growth
###### Analysis Seminar

We discuss a model for studying spontaneous phenomena in the 2d Euler equations for incompressible fluid flow. We tie the behaviour of the model to the behavior of the actual Euler equations.  (Joint work with A. Tapay.)

Speaker: Nets Katz, Caltech
Location:
Fine Hall 314
February 2, 2015
4:30pm - 5:30pm
##### Efficient numerical methods for wave scattering in periodic geometries
###### PACM/Applied Mathematics Colloquium

A growing number of technologies (communications, imaging, solar energy, etc) rely on manipulating linear waves at the wavelength scale, and accurate numerical modeling is key for device design.  I will focus on diffraction problems where time-harmonic scalar waves scatter from piecewise-uniform periodic media.  After reviewing the integral equation method, I explain two innovations that allow

Speaker: Alex Barnett, Dartmouth College
Location:
Fine Hall 214
February 3, 2015
4:30pm - 5:30pm
##### On the rationality of the logarithmic growth filtration of solutions of $p$-adic differential equations
###### Princeton University/IAS Number Theory Seminar

Please note special day.  We consider an ordinary linear $p$-adic differential equation Dy=d^ny/dx^n+a_{n-1}d^{n-1}y/dx^{n-1}+\dots+a_0y=0, a_i\in\mathbb{Z}_p[p^{-1}] whose formal solutions in $\mathbb{Q}_p$ converge in the open unit disc $|x|<1$.

Speaker: Shun Ohkubo, University of Tokyo
Location:
Fine Hall 214
February 3, 2015
4:30pm - 5:30pm
##### Height Fluctuations in Interacting Dimers
###### Mathematical Physics Seminar

Perfect matchings of Z^2(also known as non-interacting dimers on the square lattice) are an exactly solvable 2D statistical mechanics model. It is known that the associated height function behaves at large distances like a massless gaussian field, with the variance of height gradients growing logarithmically with the distance. As soon as dimers mutually interact, via e.g.

Speaker: Alessandro Giuliani, University of Rome 3
Location:
February 4, 2015
4:30pm - 5:30pm
##### Stabilization of control systems: From the water clocks to the regulation of rivers
###### Department Colloquium

A control system is a dynamical system on which one can act by using controls. For these systems a fundamental problem is the stabilization issue: Is it possible to stabilize a given unstable equilibrium by using suitable feedback laws?

Speaker: Jean-Michel Coron, Université Pierre et Marie Curie
Location:
Fine Hall 314
February 5, 2015
12:30pm - 1:30pm
##### Mobius randomness and homogeneous dynamics

Qualitative approaches to understanding the randomness of the primes offer a first step toward the extremely difficult quantitative challenge of sharply bounding sums involving the Mobius function.

Speaker: Ryan Peckner, Princeton University
Location:
Fine Hall 314
February 5, 2015
2:00pm - 3:30pm
##### The rare interaction limit in a fast-slow mechanical system
###### Ergodic Theory & Statistical Mechanics

In 2008 Gaspard and Gilbert suggested a two-step strategy to derive the 'macroscopic' heat equation from the 'microscopic' kinetic equation. Their model consisted of a chain of localized and rarely interacting hard disks.

Speaker: Domokos Szász, Budapest University of Technology
Location:
Fine Hall 601