Current Seminars
updated 11/21/ 2001
As of November 21-23
Statistical Mechanics Seminar
Topic: Interaction between electrons in Quantum Dots
Presenter: Boris Altshuler, Princeton University
Date: Wednesday, November 21, 2001, Time: 2:00 p.m., Location: Jadwin 343
Abstract: We will consider general properties of interacting fermions in a finite volume. We will show that in the case in which one-particle motion is chaotic the theoretical description of the system can be dramatically simplified. More precisely, the low energy behavior can be determined by a zero-dimensional Hamiltonian, which contains at most three unknown coupling constants. This Hamiltonian generates (or suggests revisiting) several problems that might be curious from the point of view of Mathematical Physics. To illustrate this Fermi-liquid-like approach we will discuss effects of the interactions, including exchange interaction and superconducting pairing, on the charge transport through Quantum Dots.
Week of November 26-30
Analysis Seminar
Topic: Solutions of the Maxwell-Einstein Equations
Presenter: Nina Zipser, MIT
Date: Monday, November 26, 2001, Time: 4:00 p.m., Location: Fine Hall 314
PACM Colloquium
Topic: The Traveling Salesman Problem
Presenter: William Cook, PACM, Princeton University
Date: Monday, November 26, 2001, Time: 4:00 p.m., Location: Fine Hall 214
Abstract: The traveling salesman problem, or TSP for short, is easy to state: given a number of "cities" along with the cost of travel between each pair of them, find the cheapest way of visiting all the cities and returning to your starting point. We will present a survey of recent progress in algorithms for large-scale TSP instances, including the solution of a million city instance to within 0.09% of optimality, the exact solution a 15,112-city instance, and developments in heuristic search algorithms.
Coverings of 3-Manifolds Seminar **Note change in time and location**
Topic: Introduction to Poenaru's work PART II
Presenter: David Gabai, Princeton University
Date: Tuesday, November 27, 2001, Time: 3:00 p.m., Location: Fine Hall 1201
Abstract: Valentin Poenaru has announced the following result: "The universal covering space of any closed 3-manifold is simply connected at infinity." As a corollary he gets that the universal covering space of a closed irreducible 3-manifold with infinite fundamental group is R^3. This lecture is the second part of two lectures that provide an introduction to Po's methods. Subsequent lectures will be given by Po himself.
Algebraic Geometry Seminar
Topic: TBA
Presenter: Jordan Ellenberg, Princeton University
Date: Tuesday, November 27, 2001, Time: 4:30 p.m., Location: Fine Hall 314
Mathematical Physics Seminar
Topic: Stable and unstable directions for nonlinear Schroedinger equations
Presenter: Horng-Tzer Yau, Courant Institute
Date: Tuesday, November 27, 2001, Time: 4:30 p.m., Location: Jadwin A06
Abstract: We consider a nonlinear Schroedinger equation in R^3 with a bounded local potential so that the linear Hamiltonian has two bound states and the eigenvalues satisfy some resonance condition. Suppose that the initial data is small and is near some nonlinear *excited* state. Then we give a sufficient condition on the initial data so that the solution of the nonlinear Schroedinger equation approaches a certain nonlinear *ground* state as the time tends to infinity. On the other hand, for certain finite codimensional subset in the space of initial data, we construct solutions converging to the excited states in both non-resonant and resonant cases.
Tuesdays Lecture Series
Topic: Quantum Information Theory Part III
Presenter: Peter Shor, AT&T
Date: Tuesday, November 27, 2001, Time: 4:30 p.m., Location: Fine Hall 110
Abstract: The classical theorem of Shannon from 1948 gives a simple formula for how much information can be sent through a communication channel. When we try to extend this formula to the quantum regime, we find that there is no longer a unique way to define channel capacity. We can define one capacity of a channel for transmitting classical information, and another for transmitting quantum information. To further complicate the situation, these quantum channel capacities can sometimes be changed by giving the sender and receiver additional capabilities which do not change classical capacity (e.g., shared entanglement or a back channel from the receiver to the sender). However, as we discuss, there do seem to be a small number of interesting quantum channel capacities, and several of them seem to be quantifiable by analogs of Shannon's formula. This is Part Three of a three part series.
Statistical Mechanics Seminar
Topic: The (log t)^{2/3} law of the two-dimensional asymmetric simple exclusion process
Presenter: Horng-Tzer Yau, Courant Institute
Date: Wednesday, November 28, 2001, Time: 2:00 p.m., Location: Jadwin 343
Abstract: The two-dimensional asymmetric simple exclusion process will be discussed. A classic problem is to determine the diffusion coefficient for this process and we shall show that it diverges as (log t)^{2/3} to leading order. The method applies to nearest and non-nearest neighbor asymmetric simple exclusion processes.
Department Colloquium
Topic: Topology of Lagrangian submanifolds
Presenter: Yakov Eliashberg, Institute for Advanced Study
Date: Wednesday, November 28, 2001, Time: 4:30 p.m., Location: Fine Hall 314
Abstract: This will be a survey of old and new results, as well as outstanding problems about the topology of Lagrangian submanifolds and their embeddings.
Ergodic Theory and Statistical Mechanics Seminar
Topic: Statistical properties of unimodal maps (joint with C. G. Moreira)
Presenter: Artur de Melo, Instituto de Matemática Pura e Aplicada, Rio de Janeiro, Brazil
Date: Thursday, November 29, 2001, Time: 2:00 p.m., Location: Fine Hall 224
Abstract: We consider non-trivial analytic families of unimodal maps, the main example being the real quadratic family. We give a stochastic description of the dynamics of (Lebesgue) almost every non-hyperbolic parameter. To achieve this goal we control the critical orbit, showing positive Lyapunov exponent (Collet-Eckmann condition) and polynomial recurrence with exponent 1.
Coverings of 3-Manifolds Seminar
Topic: An overview of the proof
Presenter: Valentin Poenaru, Université de Paris-Sud (Orsay)
Date: Thursday, November 29, 2001, Time: 3:00 p.m., Location: Fine Hall 1201
Abstract: We will give a non technical discussion of the various ingredients of the proof (that universal coverings of closed 3-manifolds are simply connected at infinity) and show how they hang together.
Discrete Mathematics Seminar
Topic: Graph Homomorphisms and Long Range Action
Presenter: Peter Winkler, Bell Labs
Date: Thursday, November 29, 2001, Time: 4:00 p.m., Location: Fine Hall 224
Topology Seminar
Topic: The virtual fundamental class for Gromov-Witten invariants
Presenter: Tom Parker, Michigan State University and Institute for Advanced Study
Date: Thursday, November 29, 2001, Time: 4:00 p.m., Location: Fine Hall 314
Princeton/IAS Number Theory Seminar
Topic: Deformations, derived categories and orthogonal representations
Presenter: Ted Chinburg, University of Pennsylvania
Date: Thursday, November 29, 2001, Time: 4:30 p.m., Location: Fine Hall 322
Abstract: This talk will be about joint work with Frauke Bleher on two different extensions of the deformation theory of representations of a profinite group. The first of these concerns deformations of elements in the derived category of modules for the group. The second has to do with deformations of representations into a given smooth algebraic group. I'll discuss applications to the hypercohomology of abelian varieties, and to "universal" versions of the work of Serre and Frohlich on Stiefel-Whitney classes and Hasse-Witt invariants.
Geometric Analysis Seminar
Topic: Rolling stones with flat sides: all time regularity of the interface
Presenter: Panagiota Daskalopoulos, Columbia University
Date: Friday, November 30, 2001, Time: 3:00 p.m., Location: Fine Hall 314
Week of December 3-7
Analysis Seminar
Topic: TBA
Presenter: Jalal Shata, Courant Institute
Date: Monday, December 3, 2001, Time: 4:00 p.m., Location: Fine Hall 314
PACM Colloquium
Topic: Lattice Boltzmann Method for fluid flows
Presenter: Shiyi Chen, Johns Hopkins University
Date: Monday, December 3, 2001, Time: 4:00 p.m., Location: Fine Hall 214
Coverings of 3-Manifolds Seminar
Topic: Universal covering spaces of closed 3-manifolds Part I
Presenter: Valentin Poenaru, Université de Paris-Sud (Orsay)
Date: Tuesday, December 4, 2001, Time: 3:00 p.m., Location: Fine Hall 1201
Algebraic Geometry Seminar
Topic: New examples of non-K\"ahler homotopy types
Presenter: Tony Pantev, University of Pennsylvania
Date: Tuesday, December 4, 2001, Time: 4:30 p.m., Location: Fine Hall 314
Abstract: This is a report on a recent joint work with Ludmil Katzarkov and Bertrand Toen in which we construct new examples of homotopy types which are not realizable as complex projective manifolds. In order to carry out the construction we define new homotopy invariants of a space $X$ related to the action of its fundamental group $\pi_{1}(X,x)$ on the higher homotopy groups of the schematized homotopy type $(X\otimes {\mathbb C})^{\text{sch}}$ of $X$. When $X$ is a smooth projective variety we use the Hodge decomposition on $(X\otimes {\mathbb C})^{\text{sch}}$ to deduce restrictions on these invariants and construct explicit examples which do not satisfy these restrictions.
Department Colloquium
Topic: TBA
Presenter: Sergiu Klainerman, Princeton University
Date: Wednesday, December 5, 2001, Time: 4:30 p.m., Location: Fine Hall 314
Ergodic Theory and Statistical Mechanics Seminar
Topic: Central limit theorem for some models of random walks in random enviroment and model of directed polymers
Presenter: Robert A. Minlos, Institute for Information Transmission Problems, Moscow
Date: Thursday, December 6, 2001, Time: 2:00 p.m., Location: Fine 224
Coverings of 3-Manifolds Seminar
Topic: Universal covering spaces of closed 3-manifolds Part II
Presenter: Valentin Poenaru, Université de Paris-Sud (Orsay)
Date: Thursday, December 6, 2001, Time: 3:00 p.m., Location: Fine Hall 1201
Topology Seminar
Topic: Periodic Floer homology
Presenter: Michael Hutchings, Institute for Advanced Study and Berkeley University
Date: Thursday, December 6, 2001, Time: 4:00 p.m., Location: Fine Hall 314
Princeton/IAS Number Theory Seminar
Topic: On mu-Invariants of Elliptic Curves over Q
Presenter: Mak Trifkovic, Harvard University
Date: Thursday, December 6, 2001, Time: 4:30 p.m., Location: IAS SH-101
Abstract: The talk will survey some recent work on the Iwasawa mu-invariants of p-Selmer groups of elliptic curves relative to the cyclotomic Z_p-tower over Q. The guiding conjecture in the field is due to Ralph Greenberg, and asserts that any elliptic curve over Q is isogenous to one with mu-invariant zero. I will talk about what is known about this conjecture, both by way of proof and by way of computational verification, and will present some new examples of curves with mu=0.
Geometric Analysis Seminar
Topic: Effective Schottky problem
Presenter: Samuel Grushevsky, Harvard University
Date: Friday, December 7, 2001, Time: 3:00 p.m., Location: Fine Hall 314
Week of December 10-14
Analysis Seminar
Topic: TBA
Presenter: Steve Zelditch, Johns Hopkins University
Date: Monday, December 10, 2001, Time: 4:00 p.m., Location: Fine Hall 314
Coverings of 3-Manifolds Seminar
Topic: Universal covering spaces of closed 3-manifolds Part III
Presenter: Valentin Poenaru, Université de Paris-Sud (Orsay)
Date: Tuesday, December 11, 2001, Time: 3:00 p.m., Location: Fine Hall 1201
Algebraic Geometry Seminar
Topic: TBA
Presenter: Ron Donagi, University of Pennsylvania
Date: Tuesday, December 11, 2001, Time: 4:30 p.m., Location: Fine Hall 314
Department Colloquium
Topic: Universal covering spaces of closed 3 manifolds are simply connected at infinity
Presenter: Valentin Poenaru, Université de Paris-Sud (Orsay)
Date: Wednesday, December 12, 2001, Time: 4:30 p.m., Location: Fine Hall 314
Coverings of 3-Manifolds Seminar
Topic: Universal covering spaces of closed 3-manifolds Part IV
Presenter: Valentin Poenaru, Université de Paris-Sud (Orsay)
Date: Thursday, December 13, 2001, Time: 3:00 p.m., Location: Fine Hall 1201
Princeton/IAS Number Theory Seminar
Topic: TBA
Presenter: James Parson, Princeton University
Date: Thursday, December 13, 2001, Time: 4:30 p.m., Location: TBA