Current Seminars
updated 4/25//2001

As of April 25 - 27,  2001

Statistical Mechanics Seminar
Topic: Quantum Pumps
Presenter:  Yosi Avron, Technion, Haifa
Date:  Wednesday, April 25, 2001, Time:  2:00 p.m., Location:  Jadwin 343
Abstract: Quantum pumps transfer charge, energy  etc. beween electron baths. A useful description is in terms of  adiabatic scattering theory. I shall discuss notions of optimal pumps and give their geometric characterization.  This is joint work with A. Elgart, G.M. Garf and L. Sadun.

Special Analysis Seminar  *** Note new time
Topic: How to score in Kakeya or Advanced iteration techniques in arithmetic combinatorics
Presenter: Nets Katz, Washington University at St. Louis
Date: Wednesday, April 25, 2001, Time: 3:00 p.m., Location: Fine Hall 314

Ergodic Theory and Statistical Mechanics Seminar
Topic: An ergodicity problem in the theory of Brownian Motion
Presenter: Meir Smorodinsky, Telaviv University
Date: Thursday, April 26, 2001, Time: 2:00 p.m., Location: Fine Hall 401
Abstract:  From the absolute value of a martingale, $X$, there is a unique increasing process that can be subtracted so as to obtain a martingale, $Y$. Paul Levy discovered that if $X$ is Brownian motion, $B$, then $Y$, too, is a Brownian motion.  Equivalently, Levy found that the transformation that maps $B$ to $Y$ is measure-preserving. Whether it is ergodic,was a question raised by Revuz and Yor in the book "continuous martingales and Brownian Motion". In a joint paper with Lester Dubins, it was proved that if the natural analogue of Levy's transformation for the symmetric random walk is modified to be measure-preserving, it is isomorphic to the one-sided, Bernoulli shift transformation associated with a sequence of independent random variables, each uniformly distributed on the unit interval.  In my talk I shall discuss the original question of Yor and its connecion with the symmetric random walk solution.

Ergodic Theory and Statistical Mechanics Seminar
Topic: The explicit condition for the lingering behavior of a random walk in a random environment
Presenter: Ilya Goldsheid, Queen Mary, University of London
Date: Thursday, April 26, 2001, Time: 3:00 p.m., Location: Fine Hall 401

Topology Seminar
Topic:  Gluing formulae for Seiberg-Witten invariant along 3-dimensional torus
Presenter: B. Doug Park, McMaster University
Date: Thursday, April 26, 2001, Time: 4:00 p.m., Location: Fine Hall 314
Abstract: In 1994, Seiberg and Witten introduced a very useful diffeomorphism invariant of smooth 4-manifolds.  In 1997, Morgan, Mrowka and Szabo gave fundamental gluing formulae for computing the SW-invariants of a closed 4-manifold that is gotten by gluing together D^2 x T^2 (disk cross 2-torus) and an arbitrary 4-manifold whose boundary is also T^3.  In this talk, we will present a new gluing formula for the SW-invariant along T^3, which should work in more general situations.  In particular, the new formula does not require that one of the glued-up halves is D^2 x T^2.  We will try to make the talk accessible to the non-experts.

Princeton/IAS/Rutgers Nonlinear Analysis Seminar
Topic: On critical regularity for wave maps
Presenter: T. Tao, UCLA
Date: Thursday, April 26, 2001, Time: 4:00 p.m., Location: Fine Hall 214

Princeton/IAS/Rutgers Number Theory Seminar
Topic: Stark's Question and a Strong Form of Brumer's Conjecture
Presenter: Cristian Popescu, Johns Hopkins University
Date: Thursday, April 26, 2001, Time: 4:30 p.m.. Location: Fine Hall 322

Special Statistical Mechanics and Analysis Seminar ***
Topic: Conformal Fractal Electrostatics
Presenter: Bertrand Duplantier, Serv. Phys. Theor., Saclay and Inst. H. Poincaré, Paris
Date: Friday, April 27, 2001, Time: 11:00 a.m., Location: Jadwin 343
Abstract: The distribution of the electrostatic potential near any conformally invariant fractal boundary is solved in two dimensions. This class of boundaries appears in a natural way in the statistical mechanics of random clusters at a critical point, like a percolation or an Ising cluster, a Brownian path, or a self-avoiding walk (SAW).

Graduate Student Seminar
Topic: The Nilpotent Variety in its Natural Setting
Presenter: Julianna Tymoczko, Princeton University
Date: Friday, April 27, 2001, Time: 1:30 p.m., Location: Fine Hall 214
Abstract:  The nilpotent variety lies at the crossroads of many different mathematical paths, including geometry, representation theory, combinatorics, even numerical analysis.  It is defined as follows: first, a flag in an n-dimensional complex vector space V is a nested collection of vector subspaces $V_1 \subseteq V_2 \subseteq\ldots \subseteq V_n =V$ -- namely, a line contained in a plane contained in a three-dimensional subspace contained in a ...  Given a nilpotent operator N, the collection of flags whose subspaces are each preserved by the action of N, so that $NV_i \subseteq V_i$ for each i, is called the nilpotent variety.  We will provide an introduction to this and certain closely related varieties, placing them in their context and, if time permits, discussing some recent results.

Geometry Seminar
Topic: Negative sectional curvature metrics on 3-manifolds with boundary
Presenter: Joel Hass,  Institue for Advanced Study and University of California at Davis
Date:  Friday, April 27, 2001, Time:  4:00 pm,  Location:  Fine Hall 314

Week of April 30 - May 4,  2001

Analysis Seminar
Topic: What do we want to know about Navier-Stokes equations?
Presenter: Olga Ladyzhenskaya, Steklov Institute St-Petersburg
Date: Monday, April 30, 2001, Time: 4:00 p.m., Location: Fine Hall 314

PACM Colloquium
Topic:  TBA
Presenter:  Eric Vanden-Eijnden, CIMS, New York University
Date: Monday, April 30, 2001, Time:  4:00 p.m., Location: Fine Hall 224

Discrete Mathematics Seminar
Topic: TBA
Presenter: Jeff Kahn, Rutgers University
Date: Tuesday, May 1, 2001, Time: 2:15 p.m., Location: Fine Hall 224

Topology Seminar
Topic: TBA
Presenter: Lenny Ng, MIT
Date: Thursday, May 3, 2001, Time: 4:00 p.m., Location: Fine Hall 314

Princeton/IAS/Rutgers Number Theory Seminar
Topic: TBA
Presenter: Johan de Jong , M.I.T.
Date: Thursday, May 3, 2001, Time: 4:30 p.m., Location: Fine Hall 322

Geometry Seminar
Topic: TBA
Presenter: Guan Bo, University of Tennessee
Date:  Friday, May 4, 2001, Time:  3:00 pm,  Location:  Fine Hall 314

Geometry Seminar
Topic: TBA
Presenter: C. Margerin,  Ecole Polytechnique
Date:  Friday, May 4, 2001, Time:  4:00 pm,  Location:  Fine Hall 314

Week of May 7 - May 11,  2001

PACM Colloquium
Topic: Time-dependent Taylor Vortices in Wide-Gap Spherical Couette Flow
Presenter:  Rainer Hollerbach, Geosciences, Princeton University
Date: Monday, May 7, 2001, Time:  4:00 p.m., Location: Fine Hall 224

Geometry Seminar
Topic:  Equivariant de Rham torsions
Presenter: Sebastian Goette, Tuebingen
Date:  Friday, May 11, 2001, Time:  4:00 pm,  Location:  Fine Hall 314