# Seminars & Events for 2012-2013

October 12, 2012
3:00pm - 4:00pm
##### V-soliton equations, symplectic reductions and Kahler-Ricci flow
###### Differential Geometry & Geometric Analysis Seminar

It has been widely recognized by now that in order to understand the geometry of Kahler manifolds under the Ricci flow one needs to understand a geometric-analytic version of Mori's Minimal Model Program.

Speaker: Gabriele La Nave , University of Illinois at Urbana-Champaign
Location:
Fine Hall 314
October 12, 2012
4:30pm - 5:30pm
##### Homological Mirror Symmetry for a Calabi-Yau hypersurface in projective space
###### Joint PU/IAS Symplectic Geometry Seminar

We prove homological mirror symmetry for a smooth Calabi-Yau hypersurface in projective space. In the one-dimensional case, this is the elliptic curve, and our result is related to that of Polishchuk-Zaslow; in the two-dimensional case, it is the K3 quartic surface, and our result reproduces that of Seidel; and in the three-dimensional case, it is the quintic three-fold.

Speaker: Nick Sheridan, Princeton University and IAS
Location:
Fine Hall 322
October 15, 2012
3:00pm - 5:00pm
##### Long-time analysis of 3 dimensional Ricci flow
###### Special Seminar in Geometric Analysis

Please note special time for this seminar. It is still an open problem how Perelman's Ricci flow with surgeries behaves for large times. For example, it is unknown whether surgeries eventually stop to occur and whether the full geometric decomposition of the underlying manifold is exhibited by the flow as $t \to \infty$.

Speaker: Richard Bamler, Stanford University
Location:
Fine Hall 1001
October 15, 2012
3:15pm - 4:15pm
##### Low-regularity local wellposedness of Chern-Simons-Schroedinger
###### Analysis Seminar

The Chern-Simons-Schroedinger model in two spatial dimensions is a covariant NLS-type problem that is $L^2$ critical. We prove that, with respect to the heat gauge, this problem is locally well-posed for initial data that is small in $H^s$, $s > 0$. This work is joint with Baoping Liu and Daniel Tataru.

Speaker: Paul Smith , UC Berkeley
Location:
Fine Hall 314
October 15, 2012
4:30pm - 5:30pm
##### Inaugural Minerva Lectures II: How to use linear algebraic groups
###### Minerva Lectures

How to use linear algebraic groups

Speaker: J-P. Serre, Collège de France
Location:
McDonnell Hall A01
October 15, 2012
4:30pm - 5:30pm
##### Flows and Decompositions of Games: Harmonic and Potential Games
###### PACM/Applied Mathematics Colloquium

We introduce a novel flow representation for finite games in strategic form. Based on this representation, we develop a canonical direct sum decomposition of an arbitrary game into three components, which we refer to as the potential, harmonic and nonstrategic components.

Speaker: Pablo Parrilo, MIT
Location:
Fine Hall 214
October 16, 2012
2:00pm - 3:30pm
##### The fixed point of parabolic renormalization
###### Ergodic Theory & Statistical Mechanics

Please note special day (Tuesday). I will present our joint work with O. Lanford on the parabolic renormalization operator acting on the space of simple parabolic analytic germs.

Speaker: Michael Yampolsky , Univeristy of Toronto
Location:
Fine Hall 801
October 16, 2012
4:30pm - 6:00pm
##### Derived categories of coherent sheaves on K3 surfaces
###### Algebraic Geometry Seminar

I will survey what is known and what is not known about the derived category of coherent sheaves on K3 surfaces. In particular, I shall explain how to rephrase a conjecture of Bridgeland describing the group of autoequivalences in terms of more conventional moduli spaces and period domains.

Speaker: Daniel Huybrechts , Universität Bonn
Location:
Fine Hall 322
October 17, 2012
4:30pm - 5:30pm
##### Inaugural Minerva Lectures III: Counting solutions mod p and letting p tend to infinity
###### Minerva Lectures

Counting solutions mod p and letting p tend to infinity

Speaker: J-P. Serre, Collège de France
Location:
McDonnell Hall A01
October 18, 2012
12:30pm - 1:30pm
##### Belyi's Theorem
###### Graduate Student Seminar

Belyi's Theorem provides a surprising and fairly recently-proved connection between the analytic and arithmetic theory of Riemann surfaces/algebraic curves.

Speaker: Will Sawin , Princeton University
Location:
Lewis Library 121
October 18, 2012
2:00pm - 3:30pm
##### Directed width parameters: algorithms and structural properties
###### Discrete Mathematics Seminar

Treewidth of an undirected graph measures how close the graph is to being a tree. Several problems that are NP-hard on general graphs are solvable in polynomial time on graphs with bounded treewidth. Motivated by the success of treewidth, several directed analogues of treewidth have been introduced to measure the similarity of a directed graph to a directed acyclic graph (DAG).

Speaker: Shiva Kintali, Princeton University
Location:
Fine Hall 224
October 18, 2012
2:00pm - 3:30pm
##### Regularity conditions in the CLT for linear eigenvalue statistics of Wigner matrices
###### Ergodic Theory & Statistical Mechanics

We show that the variance of centred linear statistics of eigenvalues of GUE matrices remains bounded for large $n$ for some classes of test functions less regular than Lipschitz functions. This observation is suggested by the limiting form of the variance (which has previously been computed explicitly), but it does not seem to appear in the literature.

Speaker: Percy Wong, Princeton University
Location:
Fine Hall 601
October 18, 2012
4:30pm - 5:30pm
##### On the parity of coefficients of modular forms.
###### Princeton University/IAS Number Theory Seminar

Recently Nicolas and Serre have determined the structure of the Hecke algebra acting on modular forms of level 1 modulo 2, and Serre has conjectured the existence of a universal Galois representation over

Speaker: Joël Bellaiche, Brandeis University
Location:
IAS - Simonyi Hall Seminar Room SH-101
October 18, 2012
4:30pm - 5:30pm
##### A New Spectral Sequence in Khovanov Homology
###### Topology Seminar

Khovanov homology is an invariant of links L in S^3which categorifies the Jones polynomial. In this talk, I will describe a new spectral sequence in Khovanov homology, the link forgetful spectral sequence. The spectral sequence starts at Khovanov homology and converges to the Khovanov homology of the disjoint union of the components of the link -- that is, it forgets the linking between components. The discovery of this construction was partly motivated by looking for an analog in Khovanov homology of the component-forgetting spectral sequence in link Floer homology. As an application, building on results of Kronheimer-Mrowka and Hedden-Ni, I will prove that Khovanov homology detects the unlink. Joint work with Josh Batson.

Speaker: Cotton Seed, Princeton University
Location:
Fine Hall 314
October 19, 2012
3:00pm - 5:00pm
##### Densities in Geometry, Including Isoperimetric Problems and the Poincaré Conjecture
###### Differential Geometry & Geometric Analysis Seminar

Densities or weights play an important role throughout geometry, including Perelman's proof of the Poincaré Conjecture, Lawlor's new, elegant proof of the Double Bubble Theorem, and the isoperimetric problem.

Speaker: Frank Morgan, Williams College
Location:
Fine Hall 314
October 19, 2012
4:30pm - 5:30pm
##### On the symplectic invariance of log Kodaira dimension
###### Joint PU/IAS Symplectic Geometry Seminar

Every smooth affine variety has a natural symplectic structure coming from some embedding in complex Euclidean space. This symplectic form is a biholomorphic invariant. An important algebraic invariant of smooth affine varieties is log Kodaira dimension. One can ask, to what extent is this a symplectic invariant? We show some partial symplectic invariance results for smooth affine varieties of dimension less than or equal to 3.

Speaker: Mark McLean, IAS
Location:
Fine Hall 322
October 22, 2012
3:15pm - 4:15pm
##### The large box limit for 2D NLS
###### Analysis Seminar

I will report on work in progress, in collaboration with Zaher Hani and Erwan Faou. Starting from 2D NLS set on the torus, we derive, in the appropriate weakly nonlinear regime, a new asymptotic model set in the whole space. The limiting system has very striking properties and is related to weak turbulence questions.

Speaker: Pierre Germain, Courant Institute of Mathematical Sciences
Location:
Fine Hall 314
October 22, 2012
4:30pm - 5:30pm
##### Minerva Lectures I - The virtual Haken conjecture: An overview of 3-manifold topology
###### Minerva Lectures

Waldhausen conjectured in 1968 that every aspherical 3-manifold has a finite-sheeted cover which is Haken (contains an embedded essential surface). Thurston conjectured that hyperbolic 3-manifolds have a
finite-sheeted cover which fibers over the circle. The first lecture will be an overview of 3-manifold topology in order to explain the meaning of Waldhausen's virtual Haken conjecture and Thurston's virtual fibering conjecture, and how they relate to other problems in 3-manifold theory. The second lecture will give some background on geometric group theory, including the topics of hyperbolic groups and CAT(0) cube complexes after Gromov, and explain how the above conjectures may be reduced to a conjecture of Dani Wise in geometric group theory. The third lecture will discuss the proof of Wise's conjecture, that cubulated hyperbolic groups are virtually special. Part of this result is joint work with Daniel Groves and Jason Manning. We will attempt to make these lectures accessible to a general mathematical audience at the level of a colloquium talk.

Speaker: Ian Agol , UC Berkeley
Location:
McDonnell Hall A01
October 22, 2012
4:30pm - 5:30pm
##### Parabolic Molecules: Curvelets, Shearlets, and Beyond
###### PACM/Applied Mathematics Colloquium

Anisotropic representation systems such as shearlets and curvelets have had a significant impact on applied mathematics in the last decade.

Speaker: Gitta Kutyniok, Technische Universität Berlin
Location:
Fine Hall 214
October 23, 2012
4:30pm - 6:00pm
##### A generic Nakano vanishing theorem
###### Algebraic Geometry Seminar

The genenic vanishing theorem of Green-Lazarsfeld says, roughly speaking, that the cohomology of a generic topologically trivial line bundle on a compact Kaehler manifold vanishes below a certain degree that depends only on the Albanese mapping.

Speaker: Christian Schnell , Stony Brook University
Location:
Fine Hall 322