SEMINARS
Updated: 3-1-2006
MARCH 1- MARCH 3, 2006
   
"What is Happening in Fine Hall" Seminar ***NEW
Topic: Virasoro constraints
Presenter: Andrei Okounkov, Princeton University
Date:  Wednesday, March 1, 2006, Time: 12:30 p.m., Location: Fine Hall PL
   
Number Theory Seminar
Topic: Finite orthogonal groups and elliptic curves
Presenter: Chris Hall, University of Texas at Austin
Date:  Wednesday, March 1, 2006, Time: 2:00 p.m., Location: Fine Hall 314
 
Discrete Mathematics Seminar
Topic: Mass distribution in high dimensional convex sets
Presenter: Boaz Klartag, IAS
Date:  Wednesday, March 1, 2006, Time: 2:15 p.m., Location: Fine 224
Abstract: We review some basic properties and discuss several open problems, related to the distribution of volume in general high dimensional convex sets. We will also describe some of the recent developments in the subject. No special prior knowledge will be assumed.
 
Geometry, Representation Theory, and Moduli Seminar
Topic: Lagrangian correspondences in monotone Floer theory and (2+1+1)-d TQFT
Presenter: C. Woodward, Rutgers University
Date:  Wednesday, March 1, 2006, Time: 3:00 p.m., Location: Fine Hall 214
Abstract: Using Floer theory one can define (a) a 2-category whose objects are monotone symplectic manifolds, 1-morphisms are Lagrangian correspondences, and 2-morphisms are Floer homology classes. and (b) a 2-functor which assigns to any monotone symplectic manifold a category, to any Lagrangian correspondence a functor, and to any Floer homology class a natural transformation. Our main result is that composition of functors for Lagrangian correspondences is isomorphic to the functor associated to the geometric composition. As an application, we construct an SU(2) Floer field theory for tangles.
   
Department Colloquium
Topic: On functions of stationary stochastic processes
Presenter: Benjamin Weiss, Hebrew University of Jerusalem
Date:  Wednesday, March 1, 2006, Time: 4:30 p.m., Location: Fine 314
Abstract: I will discuss two kinds of results about functions of SSP. Both will involve sequences of functions $F_n(x_1^n)$ defined on the initial n varaibles of a SSP. The first concerns universal estimates for the number of upcrossings of the sequence $F_n$ leading to constructive versions of the classical limit theorems such as Doob's martingale convergence theorem, Birkhoff's ergodic theorem and  the Shannon-Mcmillan-Breiman theorem. The second kind will chaacterize when such sequences can converge to  isomorphism invariants of SSP.
   
Ergodic Theory and Statistical Mechanics Seminar
Topic: Poisson-Dirichlet distribution for random Belyi surfaces.
Presenter: Alex Gamburd, IAS
Date:  Thursday, March 2, 2006, Time: 2:00 p.m., Location: Fine Hall 322
Abstract: Brooks and Makover introduced an approach to studying the global geometric quantities (in particular, the first eigenvalue of the Laplacian, injectivity radius, and diameter) of a "typical" compact Riemann surface of large genus based on compactifying finite-area Riemann surfaces associated with random cubic graphs; by a theorem of Belyi these are "dense" in the space of compact Riemann surfaces. The question as to how these surfaces are distributed in the Teichmuller spaces depends on the study of oriented cycles in random regular graphs with random orientation. Brooks and
Makover conjectured that asymptotically normalized cycles lengths follow Poisson-Dirichlet distribution. We will give an overview of Brooks-Makover approach and then give a proof of their conjecture.
 
Algebraic Topology Seminar
Topic: Spaces of commuting elements in Lie groups
Presenter: Fred Cohen, IAS and University of Rochester
Date:  Thursday, March 2, 2006, Time: 3:00 p.m., Location: Fine Hall 401
Abstract: Basic topological properties of the space of homomorphisms Hom(\pi, G) are developed where G is a Lie group and \pi is a discrete group. Special emphasis is on the case for which \pi a finite sum of integers.
   
Analysis Seminar
Topic: Commutative algebras of Toeplitz operators and Berezin quantization
Presenter: Nikolai Vasilevski, CINVESTAV del I.P.N.
Date:  Thursday, March 2, 2006, Time: 4:00 p.m., Location: Fine Hall 322
   
Topology Seminar
Topic: Asymptotic behavior of  Teichmuller geodesics
Presenter: Kasra Rafi, University of Connecticut
Date:  Thursday, March 2, 2006, Time: 4:30 p.m., Location: Fine Hall 314
   
Geometric Analysis Seminar
Topic: Isoperimetric inequalities and the large scale geometry of Hadamard spaces
Presenter: Stefan Wenger, Courant Institute, NYU
Date:  Friday, March 3, 2006, Time: 3:00 p.m., Location: Fine Hall 314
Abstract: We discuss some aspects of isoperimetric inequalities for k-dimensional integral currents in complete CAT(0)-spaces and in complete metric spaces X admitting cone type inequalities. We first show that such X admit isoperimetric inequalities of Euclidean type for k-dimensional cycles. This means that the volume needed to fill a cycle of volume r is bounded above by Cr^(k+1)/k for some constant C depending only on k and X. This extends a result of M. Gromov from the context of Riemannian manifolds to that of metric spaces. We furthermore show: If all asymptotic cones of X have 'dimension' strictly less than k+1 in the sense that images of Lipschitz maps from R^(k+1) have (k+1)-dimensional measure 0 then X admits an isoperimetric inequality of sub-Euclidean type for k-dimensional cycles. As a consequence we obtain that a proper cocompact Hadamard space admits isoperimetric inequalities of sub-Euclidean type above the dimension of its Euclidean rank. In particular, isoperimetric inequalities can be used to detect the Euclidean rank of proper cocompact Hadamard spaces. A conjecture of Gromov asserts that such a space should even admit linear isoperimetric inequalities above its Euclidean rank.
 
MARCH 6 -10, 2006
 
PACM Seminar
Topic: Wireless Sensing, Active Learning and Compressive Sampling
Presenter: Robert Nowak, Electrical and Computer Engineering, University of Wisconsin-Madison
Date:  Monday, March 6, 2006, Time: 4:00 p.m., Location: Fine Hall 214
Abstract: Wireless sensor networks promise a fundamentally new approach for gathering information about the physical environment via a distributed network of sensors that can communicate with each other and/or with a (usually distant) fusion center through radio-frequency wireless links. Limited power resources make energy conservation essential in these envisioned sensing systems. Thus, it becomes crucial to strategically decide when, where and how to collect samples and communicate information. Active learning methods adaptively select samples based on previous observations in order to "learn" a target function using as few samples as possible, which could clearly be advantageous in sensor network operations. Compressive sampling refers to taking non-traditional samples in the form of randomized projections of data. Recent results show that compressive sampling can allow one to reconstruct signals from far fewer samples than required by traditional Shannon-Nyquist sampling schemes, again suggesting promising opportunities for wireless sensing. In this talk I will discuss the theory of active learning and compressive sampling, connections to information and coding theory, and some intriguing potential applications to wireless sensing systems.
   
Topology Seminar *** Please note special day and time
Topic: Twisted torus knots and distance one Heegaard splittings
Presenter: Yoav Moriah, Technion
Date:  Tuesday, March 7, 2006, Time: 4:00 p.m., Location: Fine Hall 314
Abstract: (Joint work with Eric Sedgwick) It may come as a surprise to low dimensional topologists that there is no known example of a 3-manifold with a non minimal genus Heegaard splitting of distance one. We describe an infinite family of manifolds having Heegaard splittings which are candidates to be distance one. In the process we also reveal why finding such examples is so elusive.
   
Algebraic Geometry Seminar
Topic: Counts of maps to the Grassmannian and Verlinde numbers on the moduli space of rank r bundles on a curve
Presenter: Alina Marian, Yale University
Date:  Tuesday, March 7, 2006, Time: 4:30 p.m., Location: Fine Hall 322
Abstract: I will describe an intersection-theoretic relationship between the moduli space of rank r bundles on a curve C and the space of maps from C to the Grassmannian G(r, N), for large N. This relationship can be used to derive many of the Witten intersection numbers on the moduli space of bundles (for instance the volumes) as highest degree N-asymptotics in formulas of Vafa-Intriligator type, i.e. formulas which capture some of the enumerative geometry of the space of maps to the Grassmannian. One recovers thus algebraically results previously deduced via symplectic methods by Jeffrey-Kirwan and others. This is joint work with Dragos Oprea.
 
Mathematical Physics Seminar
Topic: On localization in lattice Schroedinger operators
Presenter: Jean Bourgain, Institute for Advanced Study
Date:  Tuesday, March 7, 2006, Time: 4:30 p.m., Location: Jadwin 343
 
Operation Research and Financial Engineering Seminar
Topic: A fully polynomial time approximation scheme for a variety of stochastic asset management problems
Presenter: Diego Klabjan, University of Illinois
Date:  Tuesday, March 7, 2006, Time: 4:30 p.m., Location: Room E-219, Engineering Quad
Abstract: The stochastic asset acquisition, batch replenishment, and lot-sizing problems deal with assets that change in time based on exogenous stochastic processes. We study the single asset version over a discrete finite time horizon. The computational intractability of computing an optimal policy is widely believed, and therefore approximation algorithms should be considered. Algorithms in approximate dynamic programming focus on computational efficiency and convergence; meanwhile, our focus is in providing relative bounds on the quality of the resulting policy. To the best of our knowledge, this is the first work that develops a fully polynomial time approximation scheme for these problems. In other words, for fixed K>0, we design an algorithm polynomial in the size of the problem and in 1/K, and that finds a policy that is within a factor 1+K of the value of an optimal policy. In addition, we formally prove that for the lot-sizing problem finding an optimal policy is intractable in the standard sense.
   
Discrete Mathematics Seminar
Topic: Codes and Xor graph products
Presenter: Eyal Lubetzky, Tel Aviv University
Date:  Wednesday, March 8, 2006, Time: 2:15 p.m., Location: Fine 224
Abstract: See http://www.math.princeton.edu/~bsudakov/eyal2005-2006.pdf
 
Geometry, Representation Theory, and Moduli Seminar
Topic: Introduction to double affine Hecke algebras
Presenter: Alexei Oblomkov, Princeton University and IAS
Date:  Wednesday, March 8, 2006, Time: 3:00 p.m., Location: Fine Hall 214
Abstract: Double affine Hecke algebras (DAHAs) were introduced by Cherednik at the beginning of the 1990s to prove Macdonald's conjectures on orthogonal polynomials. Later it turned out that DAHA's are useful in many other areas of mathematics, including the theory of Calogero-Moser varieties (Etingof, Ginzburg), quiver varieties (Etingof, Gan, Ginzburg, O.), and quantization of the certain algebraic varieties (Etingof, Rains, O.). I will give a definition of DAHAs and describe their key properties. In the second part of the talk I will give an overview their applications.
   
Department Colloquium
Topic: TBA
Presenter: Nikita Nekrasov, IHES
Date:  Wednesday, March 8, 2006, Time: 4:30 p.m., Location: Fine Hall 314
   
Ergodic Theory and Statistical Mechanics Seminar
Topic: Interval exchange maps, renormalisation and continued fractions
Presenter: Stefano Marmi, Universita di Piza and Princeton University
Date:  Thursday, March 9, 2006, Time: 2:00 p.m., Location: Fine Hall 322
Abstract: Interval exchange maps are characterized by combinatorial and metric data. They arise naturally as generalizations of rotations and as first return maps of linear flows on translation surfaces. The analysis of first return times on an interval (renormalisation) leads to several generalisations of the classical continued fraction algorithm (Rauzy, Veech, Zorich). A further acceleration of these schemes can be used to characterise a class of interval exchange maps of ?Roth type? for which the cohomological equation can be solved.
(the seminar is based joint work with Pierre Moussa and Jean-Christophe Yoccoz).
   
Analysis Seminar
Topic: PDEs that lose derivatives
Presenter: Joseph Kohn, Princeton University
Date:  Thursday, March 9, 2006, Time: 4:00 p.m., Location: Fine Hall 322
 
Topology Seminar
Topic: Braid groups and homotopy groups
Presenter: Fred Cohen, IAS and University of Rochester
Date:  Thursday, March 9, 2006, Time: 4:30 p.m., Location: Fine Hall 314
Abstract: This expository talk based on joint work with Jon Berrick, Yan-Loi Wong and Jie Wu addresses connections between Artin's braid groups, Vassiliev invariants and homotopy groups.
   
Geometric Analysis Seminar
Topic: TBA
Presenter: Christopher B. Croke, University of Pennsylvania
Date:  Friday, March 10, 2006, Time: 3:00 p.m., Location: Fine Hall 314
 
MARCH 13 -14, 2006
 
Mathematical Physics Seminar
Topic: Counting curves in 3-folds: a case of gauge/string duality in algebraic geometry
Presenter: Andrei Okounkov, Princeton University
Date:  Tuesday, March 14, 2006, Time: 4:30 p.m., Location: Jadwin 343
Abstract: This will be a nontechnical discussion of a conjecture about algebraic curves in 3-folds proposed by Maulik, Nekrasov, Pandharipande, and myself a few years ago and of the mathematical progress toward it so far.
   
Operation Research and Financial Engineering Seminar
Topic:

Inhomogeneous dependency modelling with time varying copulae

Presenter: Wolfgang Hürdle, Humboldt-Universitüt zu Berlin
Date:  Tuesday, March 14, 2006, Time: 4:30 p.m., Location: Room E-219, Engineering Quad
Abstract: Value-at-Risk (VaR) of a portfolio is determined by the multivariate distribution of risk factor increments. The RiskMetrics approach, a widely used methodology for VaR estimation, is based on the assumption of multivariate normality. This paper performs a better method for VaR estimation. The distribution of returns is modelled by copulae with adaptively estimated time varying parameters. The copula approach frees the modelling from the usual normality assumptions resulting in multivariate distributions that better describe the empirical characteristics of financial returns. The adaptive estimation is based on the assumption of local homogeneity: for every time point there exists an interval of time homogeneity in which the copula parameter can be well approximated by a constant. This interval is recovered from the data using local change point analysis. For a stock portfolio, copulae with time varying parameters are estimated and the VaR simulated accordingly. Backtesting underlines the improved performance of adaptive time varying copulae.
JEL classification: C 14, AMS (2000) Subject Classification : 62 M 10, 62 P 20
Keywords: Value-at-Risk, time varying copula, adapive estimation
   
"What is Happening in Fine Hall" Seminar
Topic: Conformal invariants associated with a measure
Presenter: Alice Chang, Princeton University
Date:  Wednesday, March 15, 2006, Time: 12:30 p.m., Location: Fine Hall PL
   
Number Theory Seminar
Topic: TBA
Presenter: Kathrin Bringmann, University of Wisconsin at Madison
Date:  Wednesday, March 15, 2006, Time: 2:00 p.m., Location: Fine 314
 
Discrete Mathematics Seminar
Topic: First order definability of graphs
Presenter: Oleg Pikhurko, Carnegie Mellon University
Date:  Wednesday, March 15, 2006, Time: 2:15 p.m., Location: Fine 224
Abstract: See http://www.math.princeton.edu/~bsudakov/pikhurko2005-2006.pdf
   
Geometry, Representation Theory, and Moduli Seminar
Topic: Introduction to double affine Hecke algebras
Presenter: Rahul Pandharipande, Princeton University
Date:  Wednesday, March 15, 2006, Time: 3:00 p.m., Location: Fine Hall 214
   
Department Colloquium
Topic: TBA
Presenter: Avraham Soffer, Rutgers University
Date:  Wednesday, March 15, 2006, Time: 4:30 p.m., Location: Fine Hall 314
   
Analysis Seminar
Topic: Convergence of trigonometric series
Presenter: Sergey Tikhonov, Centre de Recerca Matematica
Date:  Thursday, March 16, 2006, Time: 4:00 p.m., Location: Fine Hall 322
Abstract: We discuss three new convergence criteria (for p=\infty, 1<p<\infty, and p=1) of belonging of sums of trigonometric series to L_p. One-dimensional and multi-dimensional cases are examined. We also study Hardy-Littlewood type theorem for multiple trigonometric and Walsh series in L_p with Muckenhoupt-type weights.
   
Geometric Analysis Seminar
Topic: TBA
Presenter: Xingwang Xu, National University of Singapore
Date:  Friday, March 17, 2006, Time: 3:00 p.m., Location: Fine Hall 314
 
MARCH 20 -25, 2006
 
SPRING BREAK
 
MARCH 27 -31, 2006
 
PACM Seminar
Topic: TBA
Presenter: Scott Rickard, Electronic and Electrical Engineering, University College Dublin
Date:  Monday, March 27, 2006, Time: 4:00 p.m., Location: Fine Hall 214
 
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.
   
Topology Seminar *** Please note special date
Topic: TBA
Presenter: Richard Rimanyi, UNC Chapel Hill
Date:  Tuesday, March 28, 2006, Time: 4:30 p.m., Location: Fine 314
   
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
   
Geometry, Representation Theory, and Moduli Seminar
Topic: TBA
Presenter: K. Costello, Chicago University
Date:  Wednesday, March 29, 2006, Time: 3:00 p.m., Location: Fine Hall 214
 
Department Colloquium
Topic: TBA
Presenter: Gang Tian, Princeton University
Date:  Wednesday, March 29, 2006, Time: 4:30 p.m., Location: Fine Hall 314
   
Topology Seminar
Topic: TBA
Presenter: Elisenda Grigsby, UC Berkeley
Date:  Thursday, March 30, 2006, Time: 4:30 p.m., Location: Fine Hall 314
 
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
 
APRIL 3 - 7, 2006
 
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.
   
Operation Research and Financial Engineering Seminar
Topic: TBA
Presenter: Adrian Lewis, Cornell University
Date:  Tuesday, April 4, 2006, Time: 4:30 p.m., Location: Room E-219, Engineering Quad
   
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
   
Algebraic Geometry Seminar *** Please note special date
Topic: TBA
Presenter: M. Popa, University of Chicago
Date:  Thursday, April 6, 2006, Time: 4:30 p.m., Location: TBA
 
Topology Seminar
Topic: TBA
Presenter: Mikhail Khovanov, Columbia University
Date:  Thursday, April 6, 2006, Time: 4:30 p.m., Location: Fine Hall 314
 
Geometric Analysis Seminar
Topic: TBA
Presenter: Robert Hardt, Rice University
Date:  Friday, April 7, 2006, Time: 3:00 p.m., Location: Fine Hall 314
 
APRIL 10 - 14, 2006
 
PACM Seminar
Topic: TBA
Presenter: Lisa Fauci, Mathematics, Tulane University
Date:  Monday, April 10, 2006, Time: 4:00 p.m., Location: Fine Hall 214
 
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.
 
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.
   
Operation Research and Financial Engineering Seminar
Topic: TBA
Presenter: Anja Sturm, University of Delaware
Date:  Tuesday, April 11, 2006, Time: 4:30 p.m., Location: Room E-219, Engineering Quad
 
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
   
Geometric Analysis Seminar
Topic: TBA
Presenter: Hubert Bray, Duke University
Date:  Friday, April 14, 2006, Time: 3:00 p.m., Location: Fine Hall 314
 
APRIL 17 - 21, 2006
 
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.
 
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
 
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
 
Analysis Seminar
Topic: TBA
Presenter: Pierre Germain, Ecole Polytechnique, Palaiseau
Date:  Thursday, April 20, 2006, Time: 4:00 p.m., Location: Fine Hall 322
   
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
 
APRIL 24 - 28, 2006
 
Mathematical Physics Seminar
Topic: TBA
Presenter: P. Hislop, University of Kentucky
Date:  Tuesday, April 25, 2006, Time: 4:30 p.m., Location: Jadwin 343
 
Department Colloquium
Topic: TBA
Presenter: Yair Minsky, Yale University
Date:  Wednesday, April 26, 2006, Time: 4:30 p.m., Location: Fine Hall 314
 
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.
   
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
 
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
 
MAY 1 - 5, 2006
 
Department Colloquium
Topic: TBA
Presenter: Brian Conrad, University of Michigan
Date:  Wednesday, May 3, 2006, Time: 4:30 p.m., Location: Fine Hall 314
   
Geometric Analysis Seminar
Topic: TBA
Presenter: Fernando Marques, Stanford University
Date:  Friday, May 5, 2006, Time: 3:00 p.m., Location: Fine Hall 314