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MARCH 22 -25, 2006 |
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| Joint Homogenous Spaces and Number Theory Seminar |
| Topic: |
Estimates from below for the remainder in local Weyl's law |
| Presenter: |
D. Jakobson, McGill University |
| Date: |
Friday, March 24, 2006, Time: 11:00 a.m., Location: IAS S-101 |
| Abstract: |
We obtain asymptotic lower bounds for the spectral function of the Laplacian and for the remainder in local Weyl's law on compact manifolds. In the negatively curved case, thermodynamic formalism is applied to improve the estimates. Our results can be considered pointwise versions (on a general manifold) of Hardy's lower bounds for the error term in the Gauss circle problem. Our results develop and extend the unpublished thesis of A. Karnaukh. This is joint work with I. Polterovich (Univ. of Montreal) |
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MARCH 27 - 31, 2006 |
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| PACM Seminar |
| Topic: |
Sparsity and Source Separation: just DUET |
| Presenter: |
Scott Rickard, Electronic and Electrical Engineering, University College Dublin |
| Date: |
Monday, March 27, 2006, Time: 4:00 p.m., Location: Fine Hall 214 |
| Abstract: |
Detroit MI, April 2001.
A woman is found stabbed to death in the kitchen of her apartment. The police find that a video recorder in the family room was recording during the murder, but the camera lens cap was on and, as a result, the video portion of the recording reveals nothing. The audio channel of the recording, however, has captured the entire crime. Unfortunately, a stereo was playing loud schmaltzy music during the conversation leading up to the assault, and the speech on the recording cannot be understood. Fortunately, the police have the tape that was playing at the time, but traditional approaches for removing the interfering music from the mixture fail.
Princeton NJ, June 2002.
Murder victim gets the last word - case closed.
In this talk I will discuss the sparse revolution which is occurring in signal processing which is allowing researchers to solve systems of equations with more unknowns than constraints. We've all been taught that if we have 2 unknowns, we require 2 equations to solve for the unknowns. For 3 unknowns, we need 3 equations (and 4 require 4, and so on...). This is not true - as long as you're willing to cheat. For example, we 'cheat' in cocktail parties when we listen to one person while a dozen speak in the background. Mathematically, we would need 13 ears to eliminate the dozen unwanted speakers to allow us to focus on the one speaker of interest. The DUET Blind Source Separation Algorithm mimics this human auditory ability in that it can separate an arbitrary number of sources from just two mixtures (such as those heard by two ears in a cocktail party). I will reveal how we use sparsity to cheat and thus solve the problem of more unknowns than equations. Also, I will discuss various related modifications of DUET, one of which was used to solve the above murder case. This talk will feature a live demonstration of DUET. |
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| Algebraic Geometry Seminar |
| Topic: |
Nef but not semi-ample line bundles over finite fields |
| Presenter: |
Burt Totaro, Cambridge Univ. |
| Date: |
Tuesday, March 28, 2006, Time: 4:30 p.m., Location: Fine Hall 322 |
| Abstract: |
We give the first example of a nef line bundle L on a smooth projective variety over a finite field such that L is not semi-ample. (That is, no power of L is basepoint-free.) Our examples give a negative answer to a question by Keel. |
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| Topology Seminar *** Please note special date |
| Topic: |
Thom polynomials |
| Presenter: |
Richard Rimanyi, UNC Chapel Hill |
| Date: |
Tuesday, March 28, 2006, Time: 4:30 p.m., Location: Fine 314 |
| Abstract: |
In certain situations global topology may force singularities. For example, the topology of the Klein bottle
forces self-intersections when mapped into 3-space. Any map of the projective plane must have
at least cusp singularities when mapped into the plane. The topology of a manifold may force any differential
form on it to degenerate at certian points. In a family of vector bundles over a complex curve some must
degenerate to a non-stable bundle (in the GIT sense), depending on the topology of the family.
In a family of vector bundle maps---arranged according to a directed graph (quiver)---some may be forced to
degenerate. In families of linear spaces some have special incidence with some other fixed ones (Schubert
calculus). --- These degenerations are governed by a unified notion in equivariant cohomology, the Thom
polynomial of "singularities". In the lecture I will review Thom polynomials, computational strategies (interpolation,
localization, Grobner basis), show examples and applications. |
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| Discrete Mathematics Seminar |
| Topic: |
Making, Breaking, Avoiding, Enforcing |
| Presenter: |
Tibor Szabo, ETH |
| Date: |
Wednesday, March 29, 2006, Time: 2:15 p.m., Location: Fine 224 |
| Abstract: |
See http://www.math.princeton.edu/~bsudakov/szabo2005-2006.pdf |
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| Geometry, Representation Theory, and Moduli Seminar |
| Topic: |
The B model partition function and the holomorphic anomaly equation |
| Presenter: |
Kevin Costello, University of Chicago |
| Date: |
Wednesday, March 29, 2006, Time: 3:00 p.m., Location: Fine Hall 214 |
| Abstract: |
If X is a Calabi-Yau, the B model partition function is a state in the Fock space of the symplectic vector space H*(X)((t)). The holmorphic anomaly equation tells us how this behaves when we vary the complex structure on X : the partition function is flat for a certain natural connection on the Fock space. I'll discuss some aspects of the construction of the partition function and the proof of the holomorphic anomaly. |
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| Department Colloquium |
| Topic: |
Geometry of lower dimensional manifolds |
| Presenter: |
Gang Tian, Princeton University |
| Date: |
Wednesday, March 29, 2006, Time: 4:30 p.m., Location: Fine Hall 314 |
| Abstract: |
I will first review some classical facts on Riemann
surfaces and their recent variations in geometric analysis. Then I
will discuss Perelman's work on the Ricci flow and its application
towards the Poincare conjecture. In the end, I will discuss
geometric equations in dimension 4 and how they can be applied to
studying geoemtry of 4-manifolds. |
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| Ergodic Theory and Statistical Mechanics Seminar |
| Topic: |
The Hecke correspondence and equidistribution of eigenfunctions |
| Presenter: |
Lior Silberman, Institute for Advanced Study |
| Date: |
Thursday, March 30, 2006, Time: 2:00 p.m., Location: Fine Hall 322 |
| Abstract: |
I will give an introduction to the Hecke correspondence on (quotients) of the upper half-plane and the space of symmetric
postive-definite matrices. The diophantine and geometric properties of
these correspondences imply strong restrictions on the concentration of
eigenfunctions. |
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| Algebraic Topology Seminar |
| Topic: |
Homotopy exponents of compact simple Lie groups |
| Presenter: |
Don Davis, Lehigh University |
| Date: |
Thursday, March 30, 2006, Time: 3:00 p.m., Location: Fine Hall 401 |
| Abstract: |
We compare lower bounds for homotopy exponents of compact simple Lie groups obtained from v1-periodic homotopy theory
with upper bounds obtained from various fibrations,
following ideas of Theriault, often obtaining very good agreement. |
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| Topology Seminar |
| Topic: |
TBA |
| Presenter: |
Elisenda Grigsby, UC Berkeley |
| Date: |
Thursday, March 30, 2006, Time: 4:30 p.m., Location: Fine Hall 314 |
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| Arithmetic Homogenous Spaces Seminar |
| Topic: |
Some modular generating functions for arithmetic cycles |
| Presenter: |
Stephen Kudla, IAS |
| Date: |
Friday, March 31, 2006, Time: 11:00 a.m., Location: IAS S-101 |
| Abstract: |
In this talk I will give an overview of joint work with M. Rapoport and T. Yang on the construction of generating series whose coefficients are the classes of special divisors and 0-cycles on the arithmetic surfaces attached to Shimura curves. These series are the q expansions of modular forms of genus 1 and 2 respectively. I will then describe an arithmetic inner product formula and an arithmetic Siegel-Weil formula involving these forms. If time permits at the end, I will discuss some open problems. |
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| Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Qing Jie, UC Santa Cruz |
| Date: |
Friday, March 31, 2006, Time: 3:00 p.m., Location: Fine Hall 314 |
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APRIL 3 - 7, 2006 |
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| Math Graduate Student Seminar |
| Topic: |
TBA |
| Presenter: |
Louis-Pierre Arguin, Princeton University |
| Date: |
Tuesday, April 4, 2006, Time: 12:30 p.m., Location: Fine Hall 224 |
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| Mathematical Physics Seminar |
| Topic: |
Hardy inequalities for many particles |
| Presenter: |
Ari Laptev, KTH |
| Date: |
Tuesday, April 4, 2006, Time: 4:30 p.m., Location: Jadwin 343 |
| Abstract: |
We prove some inequalities of Hardy type for many particles. In particular, we show how introducing Aharonov-Bohm magnetic fields could give such inequalities for two-dimensional particles. It turned out that 2D Hardy inequalities hold also for fermions. |
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| Operation Research and Financial Engineering Seminar |
| Topic: |
Solving nonsmooth optimization problems |
| Presenter: |
Adrian Lewis, Cornell University |
| Date: |
Tuesday, April 4, 2006, Time: 4:30 p.m., Location: Room E-223, Engineering Quad |
| Abstract: |
Nonsmooth functions abound in optimization, and challenge traditional computational approaches with their potential pathology. In typical examples, however, the nonsmoothness is highly structured. Using examples from eigenvalue optimization and robust control, I will survey various nonsmooth structures, and their uses in understanding sensitivity and algorithms, focusing in particular on partly smooth, prox-regular, and semi-algebraic functions. |
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| Discrete Mathematics Seminar |
| Topic: |
TBA |
| Presenter: |
Daniel Katz, Princeton University |
| Date: |
Wednesday, April 5, 2006, Time: 2:15 p.m., Location: Fine 224 |
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| Geometry, Representation Theory, and Moduli Seminar |
| Topic: |
TBA |
| Presenter: |
Michael Usher, Princeton University |
| Date: |
Wednesday, April 5, 2006, Time: 3:00 p.m., Location: Fine Hall 214 |
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| Algebraic Geometry Seminar *** Please note special date |
| Topic: |
TBA |
| Presenter: |
Mihnea Popa, University of Chicago |
| Date: |
Thursday, April 6, 2006, Time: 4:30 p.m., Location: TBA |
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| Topology Seminar |
| Topic: |
TBA |
| Presenter: |
Mikhail Khovanov, Columbia University |
| Date: |
Thursday, April 6, 2006, Time: 4:30 p.m., Location: Fine Hall 314 |
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| Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Robert Hardt, Rice University |
| Date: |
Friday, April 7, 2006, Time: 3:00 p.m., Location: Fine Hall 314 |
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APRIL 10 - 14, 2006 |
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| PACM Seminar |
| Topic: |
Spirochetes and spermatozoa: Fluid dynamic models of microorganism motility |
| Presenter: |
Lisa Fauci, Mathematics, Tulane University |
| Date: |
Monday, April 10, 2006, Time: 4:00 p.m., Location: Fine Hall 214 |
| Abstract: |
The observed swimming behavior of a motile microorganism is the result of a complex interplay between mechanisms of internal force generation, the passive elastic properties of its structure, and a surrounding viscous fluid. In this talk, we will focus on two very different types of microorganisms: the spirochetes, which are a type of bacteria characterized by an efficient mode of motility that allows them to screw through viscous fluids and mucosal surfaces, and spermatozoa, that undulate as a result of the action of thousands of molecular motors positioned along the flagellum. We will present mathematical and computational models that couple the internal force generating mechanisms of these microorganisms with external fluid mechanics. We will describe our methodology, which includes both the method of regularized Stokeslets and the immersed boundary method. We will discuss recent successes as well as challenges associated with these models. |
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| PACM Seminar ***Note special date |
| Topic: |
From Maxwell demon to Brownian refrigerator |
| Presenter: |
Christian Van den Broeck, Theoretical Physics, Hasselt University, Belgium |
| Date: |
Tuesday, April 11, 2006, Time: 4:00 p.m., Location: Fine Hall 214 |
| Abstract: |
Maxwell was under the impression that it should be possible to violate the second law of thermodynamics provided one could operate on a molecular scale. This comment was the beginning of a discussion stretching over the whole of the 20th century involving outstanding physicists including Smoluchowski, Onsager, Szilard, Feynman and Landauer. The issue has now become of more than academic interest because of recent developments in nanotechnology and molecular biology. We present a simplification of the Feynman ratchet that can be studied in detail by hard disk molecular dynamics and for which an exact microscopic calculation is possible. We will show how this construction can be used as a Brownian motor but also as a Brownian heat pump and refrigerator. |
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| Mathematical Physics Seminar |
| Topic: |
Integrable models and operator algebras |
| Presenter: |
Detlev Buchholz, University of Goettingen |
| Date: |
Tuesday, April 11, 2006, Time: 4:30 p.m., Location: Jadwin 343 |
| Abstract: |
Recently, it has been possible to establish rigorously the existence of an abundance of 1+1-dimensional relativistic quantum field theories with factorizing scattering matrices by operator-algebraic means. This novel approach, which is complementary to the advanced methods of constructive quantum field theory, settles some long-standing questions in the context of integrable models (form-factor program) and sheds new light on the problem of constructing quantum field theories. In this talk, a survey is given of the basic ideas, results and perspectives of this approach. |
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| Operation Research and Financial Engineering Seminar |
| Topic: |
TBA |
| Presenter: |
Massimo Marinacci |
| Date: |
Tuesday, April 11, 2006, Time: 4:30 p.m., Location: Room E-209, Engineering Quad |
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| Discrete Mathematics Seminar |
| Topic: |
TBA |
| Presenter: |
Roy Meshulam, Technion and IAS |
| Date: |
Wednesday, April 12, 2006, Time: 2:15 p.m., Location: Fine 224 |
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| Geometry, Representation Theory, and Moduli Seminar |
| Topic: |
TBA |
| Presenter: |
Alina Marian, Yale University |
| Date: |
Wednesday, April 12, 2006, Time: 3:00 p.m., Location: Fine Hall 214 |
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| Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Hubert Bray, Duke University |
| Date: |
Friday, April 14, 2006, Time: 3:00 p.m., Location: Fine Hall 314 |
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APRIL 17 - 21, 2006 |
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| PACM Seminar |
| Topic: |
Turbulence and Large-scale Circulation in the Ocean and Atmosphere |
| Presenter: |
Geoff Vallis, Geosciences / Atmospheric & Oceanic Sciences, Princeton University |
| Date: |
Monday, April 17, 2006, Time: 4:00 p.m., Location: Fine Hall 214 |
| Abstract: |
The large-scale circulation is not only affected but is essentially effected by turbulent flows. This turbulence is not the small-scale turbulence that is (unfortunately) sometimes connoted by the word turbulence, but is turbulence up to the scale of the large-scale flow itself. This is largely two-dimensional, so-called geostrophic turbulence. We will discuss what is known and what is unknown about such flow, the problems of both simulating it and of understanding it, and whether these two are the same. |
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| Mathematical Physics Seminar |
| Topic: |
TBA |
| Presenter: |
Y. Peres, University of California, Berkeley |
| Date: |
Tuesday, April 18, 2006, Time: 4:30 p.m., Location: Jadwin 343 |
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| Discrete Mathematics Seminar |
| Topic: |
Shannon capacity and privileged users |
| Presenter: |
Noga Alon, Tel Aviv University and IAS |
| Date: |
Wednesday, April 19, 2006, Time: 2:15 p.m., Location: Fine 224 |
| Abstract: |
See http://www.math.princeton.edu/~bsudakov/alon2005-2006.pdf |
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| Geometry, Representation Theory, and Moduli Seminar |
| Topic: |
TBA |
| Presenter: |
M. Wijnholt, Princeton University |
| Date: |
Wednesday, April 19, 2006, Time: 3:00 p.m., Location: Fine Hall 214 |
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| Department Colloquium |
| Topic: |
TBA |
| Presenter: |
Yuval Peres, University of California, Berkeley |
| Date: |
Wednesday, April 19, 2006, Time: 4:30 p.m., Location: Fine Hall 314 |
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| Analysis Seminar |
| Topic: |
Weak-strong uniqueness for the Navier-Stokes equation |
| Presenter: |
Pierre Germain, Ecole Polytechnique, Palaiseau |
| Date: |
Thursday, April 20, 2006, Time: 4:00 p.m., Location: Fine Hall 322 |
| Abstract: |
There exist classes of strong solutions of the Navier-Stokes equation such that: if a weak solution belongs to them, it is unique. We say then that weak-strong uniqueness holds. Serrin criterion is the first example of such a result. We will discuss new results which generalize Serrin criterion. |
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| Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Mu-Tao Wang, Columbia University |
| Date: |
Friday, April 21, 2006, Time: 3:00 p.m., Location: Fine Hall 314 |
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APRIL 24 - 28, 2006 |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Martin Olsson, U. Texas |
| Date: |
Tuesday, April 25, 2006, Time: 4:30 p.m., Location: Fine Hall 322 |
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| Mathematical Physics Seminar |
| Topic: |
TBA |
| Presenter: |
Peter Hislop, University of Kentucky |
| Date: |
Tuesday, April 25, 2006, Time: 4:30 p.m., Location: Jadwin 343 |
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| Department Colloquium |
| Topic: |
TBA |
| Presenter: |
Yair Minsky, Yale University |
| Date: |
Wednesday, April 26, 2006, Time: 4:30 p.m., Location: Fine Hall 314 |
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| Analysis Seminar |
| Topic: |
Optimal transportation and Ricci curvature for metric measure spaces |
| Presenter: |
Karl-Theodor Sturm, University of Bonn |
| Date: |
Thursday, April 27, 2006, Time: 4:00 p.m., Location: Fine Hall 322 |
| Abstract: |
We introduce and analyze generalized Ricci curvature bounds for
metric measure spaces (M,d,m), based on convexity properties of
the relative entropy Ent(. | m). For Riemannian manifolds,
Curv(M,d,m) \ge K if and only if Ric_M\ge K on M. For the
Wiener space, Curv(M,d,m)=1. One of the main results is that these lower
curvature bounds are stable under (e.g. measured Gromov-Hausdorff)
convergence. Moreover, we introduce a curvature-dimension condition
CD(K,N) being more restrictive than the curvature bound
Curv(M,d,m)\ge K. For Riemannian manifolds, CD(K,N) is equivalent to
Ric_M(\xi,\xi)\ge K\cdot |\xi|^2 and dim}(M)\le N.
Condition CD(K,N) implies sharp version of the
Brunn-Minkowski inequality, of the Bishop-Gromov volume comparison
theorem and of the Bonnet-Myers theorem. Moreover, it allows to
construct canonical Dirichlet forms with {Gaussian upper and lower
bounds} for the corresponding heat kernels. |
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| Topology Seminar |
| Topic: |
TBA |
| Presenter: |
Andras Stipsicz, Renyi Institute of Mathematics |
| Date: |
Thursday, April 27, 2006, Time: 4:30 p.m., Location: Fine Hall 314 |
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| Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Christina W. Tonnessen-Friedman, Union College |
| Date: |
Friday, April 28, 2006, Time: 3:00 p.m., Location: Fine Hall 314 |
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MAY 1 - 5, 2006 |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Mark Andrea de Cataldo, Stony Brook, State University of New York |
| Date: |
Tuesday, May 2, 2006, Time: 4:30 p.m., Location: Fine Hall 322 |
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| Geometry, Representation Theory, and Moduli Seminar |
| Topic: |
TBA |
| Presenter: |
Alexander Braverman, Brown University |
| Date: |
Wednesday, May 3, 2006, Time: 3:00 p.m., Location: Fine Hall 214 |
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| Department Colloquium |
| Topic: |
Asymptotics for prime specialization over finite fields |
| Presenter: |
Brian Conrad, University of Michigan |
| Date: |
Wednesday, May 3, 2006, Time: 4:30 p.m., Location: Fine Hall 314 |
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| Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Fernando Marques, Stanford University |
| Date: |
Friday, May 5, 2006, Time: 3:00 p.m., Location: Fine Hall 314 |
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MAY 15 - 19, 2006 |
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| Operation Research and Financial Engineering Seminar |
| Topic: |
TBA |
| Presenter: |
Pauline Barrieu |
| Date: |
Tuesday, May 16, 2006, Time: 4:30 p.m., Location: Room E-219, Engineering Quad |
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