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NOVEMBER 25-28, 2003 |
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| Mathematical Physics Brown Bag Lunch Talk | |
| Topic: | Strange Heat Flux in (an) Harmonic Networks |
| Presenter: | Jean-Pierre Eckmann, Université de Genève |
| Date: | Tuesday, November 25, 2003, Time: 12:30 p.m., Location: Jadwin 343 |
| Abstract: | In this work with E. Zabey, we produce examples of networks of harmonic springs in which heat flows in a counterintuitive fashion from certain cold reservoirs to hot reservoirs. And, even worse, there can be circulation of heat in such networks. |
| Mathematical Physics Seminar | |
| Topic: | Speed and Stability of Pattern-Forming Fronts |
| Presenter: | Jean-Pierre Eckmann, Université de Genève |
| Date: | Tuesday, November 25, 2003, Time: 4:30 p.m., Location: Jadwin A06 |
| Abstract: | I will discuss 2 papers concerning the pattern forming Swift-Hohenberg equation. One paper (with Pierre Collet) deals with a universal bound on the propagation speed, which tells us how fast patterns can invade empty space. The other (with Guido Schneider) deals with a explanation of why these advancing patterns are actually stable under perturbation of the initial condition. This problem, which has long resisted proof has an astonishingly simple solution (at least in principle): The instabilities do not have "enough time" to really do any harm. |
| Algebraic Geometry Seminar | |
| Topic: | Simple Hironaka resolution |
| Presenter: | Jaroslaw Wlodarczyk, Purdue University |
| Date: | Tuesday, November 25, 2003, Time: 4:30 p.m., Location: Fine Hall 322 |
| Abstract: | Building upon works of O.Villamyor, Encinas-Villamayor and Bierstone-Milman we give a short proof of Hironaka resolution teorems. We put particular emphasis on canonicity and functoriality of the algorithm. Introduced here idea of "Homogenized ideals" gives apriorie canonicity of the resolution procedure and radically simplifies the proof. |
| Joint Institute for Advanced Study/Princeton University Complex Geometry Seminar ***Please note change in time | |
| Topic: | Hodge theory and Geometry, II |
| Presenter: | Phillip Griffiths, Institute for Advanced Study |
| Date: | Wednesday, November 26, 2003, Time: 1:30 p.m., Location: Fine Hall 401 |
| Discrete Mathematics Seminar | |
| Topic: | Random geometric graphs |
| Presenter: | Bela Bollobas, Memphis and Cambridge Universities |
| Date: | Wednesday, November 26, 2003, Time: 2:15 p.m., Location: Fine Hall 322 |
| Abstract: | See www.math.princeton.edu/~bsudakov/bela2003.ps |
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DECEMBER 1 - 5, 2003 |
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| Discrete Mathematics Seminar *** Please note change in date, time, and location | |
| Topic: | How many ways can one draw a graph? |
| Presenter: | János Pach, MSRI and New York University |
| Date: | Tuesday, December 2, 2003, Time: 2:30 p.m., Location: Fine Hall 214 |
| Abstract: | See www.math.princeton.edu/~bsudakov/pach2003.ps |
| Algebraic Geometry Seminar | |
| Topic: | Algebraic Sets of Minimal Degree |
| Presenter: | Sorin Popescu, Stony Brook |
| Date: | Tuesday, December 2, 2003, Time: 4:30 p.m., Location: Fine Hall 322 |
| Abstract: | Algebraic varieties of minimal degree were classified by Del Pezzo (for surfaces) and Bertini (in all dimensions). For various reasons the notion of ``minimal degree'' is not a very sensible one for algebraic sets in general, but there are other good geometric conditions that mean "minimal degree" in the irreducible case and generalize well. In recent work with Eisenbud, Green and Hulek we have achieved a rather simple classification from which a number of surprising algebraic and geometric results flow. It turns out also that this classification coincides with that of 2-regular reduced ideals. |
| Mathematical Physics Seminar | |
| Topic: | Anomalous universality in the anisotropic Ashkin-Teller model |
| Presenter: | Alessandro Giuliani, Rome University (La Sapienza) |
| Date: | Tuesday, December 2, 2003, Time: 4:30 p.m., Location: Jadwin A06 |
| Abstract: | The Ashkin-Teller model is a two dimensional spin system, in which two Ising layers interact via a four-spin interaction. We consider the case of weak anisotropy (slight a-symmetry between the two Ising layers) and weak coupling. We show that the system admits two critical temperatures whose difference varies continuously with the strength of the coupling, scaling with an anomalous exponent.The specific heat diverges logarithmically at the critical points (as for Ising) but the constant in front of the logarithm is renormalized by an anomalous critical exponent. The talk is based on a joint work with V. Mastropietro. |
| Geometry, Representation Theory, and Moduli Seminar | |
| Topic: | Blow-up formulas in Seiberg-Witten theory: an exposition |
| Presenter: | Zoltan Szabo, Princeton University |
| Date: | Wednesday, December 3, 2003, Time: 3:00 p.m., Location: Fine Hall 214 |
| Department Colloquium | |
| Topic: | Homological mirror symmetry for Fano surfaces |
| Presenter: | Denis Auroux, MIT |
| Date: | Wednesday, December 3, 2003, Time: 4:30 p.m., Location: Fine Hall 314 |
| Abstract: | This talk will be an attempt, aimed at non-specialists, to explain the statement of the homological mirror symmetry conjecture, and describe a procedure for its verification on concrete examples, in a special case where essentially no understanding of symplectic topology is required. |
| Ergodic Theory and Statistical Mechanics Seminar | |
| Topic: | Critical percolation on the plane and conformal invariance of its scaling limit |
| Presenter: | Vassilios Papathanakos, Princeton University |
| Date: | Thursday, December 4, 2003, Time: 2:00 p.m., Location: Fine Hall 224 |
| Abstract: | We will present the recent result of S. Smirnov, who proved the conformal invariance of the scaling limit of critical percolation on the triangular lattice. After a quick review of the percolation model, we will discuss its scaling limit and the sense in which it is conformally invariant. Then, we will formulate the Smirnov theorem and describe details of its proof. Finally, we will give an update on recent developments on this topic |
| Joint Institute for Advanced Study/Princeton University Number Theory Seminar | |
| Topic: | TBA |
| Presenter: | Manjul Bhargava, Princeton University |
| Date: | Thursday, December 4, 2003, Time: 4:15 p.m., Location: Fine Hall 322 |
| Topology Seminar | |
| Topic: | The Gromov invariant and the Donaldson-Smith standard surface count |
| Presenter: | Michael Usher, MIT |
| Date: | Thursday, December 4, 2003, Time: 4:30 p.m., Location: Fine Hall 314 |
| Abstract: | I will discuss the equivalence of an invariant associated to four-dimensional symplectic Lefschetz fibrations that was introduced by Simon Donaldson and Ivan Smith to the Gromov invariant of Cliff Taubes which counts pseudoholomorphic submanifolds of symplectic 4-manifolds. As a consequence of this equivalence and of earlier work of Smith, there follows a new proof of a duality relation in the Gromov invariants (originally discovered by Taubes using Seiberg-Witten theory) that does not rely on gauge theory. |
| Geometric Analysis Seminar | |
| Topic: | Determinants of Laplacians and the inverse resonance problem |
| Presenter: | Peter Perry, University of Kentucky |
| Date: | Friday, December 5, 2003, Time: 3:00 p.m., Location: Fine Hall 314 |
| Abstract: | This talk concerns joint work with David Borthwick (Emory University) and Chris Judge (University of Indiana). If $X$ is a Riemann surface of finite geometry and infinite area, the Laplacian on $X$ will have at most finitely many eigenvalues, and possibly no eigenvalues, but infinitely many scattering resonances--complex numbers which like the eigenvalues correspond to normal modes of oscillation, but have nonzero imaginary part representing an exponential decay rate for the energy of the normal mode in any finite region. We define a determinant of the Laplacian whose zeros are the scattering resonances and use it to prove a compactness theorem for metrics on $X$ which have constant curvature outside a compact set and have the same eigenvalues and scattering resonances. We also prove that Selberg's zeta function for $X$ is a meromorphic function of order two for \emph{any} surface with finite geometry. As an application to the theory of discrete groups, we prove that if $\Gamma$ is a finitely generated discrete subgroup of $SL(2,\mathbb{R})$, the set of traces ${\mathrm{Tr}}(\gamma)$ determine the conjugacy class of $\Gamma$ in $SL(2,\mathbb{R})$ up to finitely many possibilities. |
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DECEMBER 8 - 12, 2003 |
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| Algebraic Geometry Seminar | |
| Topic: | Combinatorial and tautological classes on the moduli space of curves |
| Presenter: | Gabriele Mondello, Institute for Advanced Study |
| Date: | Tuesday, December 9, 2003, Time: 4:30 p.m., Location: Fine Hall 322 |
| Abstract: | Every presentation of the moduli space of curves gives rise to "natural" cohomology classes. The so-called tautological classes appear in the classical algebro-geometric setting. On the other side, the cellular decomposition of the moduli space via the ribbon graph complex allowed Witten to define some interesting cycles on it, which are called combinatorial. The aim of this talk is to illustrate the main ideas involved in the proof of the so-called Witten-Kontsevich conjecture: combinatorial classes are tautological. |
| Mathematical Physics Seminar | |
| Topic: | TBA |
| Presenter: | Eugene Trubowitz, ETH, Zurich |
| Date: | Tuesday, December 9, 2003, Time: 4:30 p.m., Location: Jadwin A06 |
| Discrete Mathematics Seminar | |
| Topic: | TBA |
| Presenter: | Jeff Kahn, Rutgers University |
| Date: | Wednesday, December 10, 2003, Time: 2:15 p.m., Location: Fine Hall 322 |
| Geometry, Representation Theory, and Moduli Seminar | |
| Topic: | TBA |
| Presenter: | Tony Pantev, University of Pennsylvania |
| Date: | Wednesday, December 10, 2003, Time: 3:00 p.m., Location: Fine Hall 214 |
| Department Colloquium | |
| Topic: | Boundaries of Non-Compact Groups; an Update |
| Presenter: | Hillel Furstenberg, Yale University and Hebrew University of Jerusalem |
| Date: | Wednesday, December 10, 2003, Time: 4:30 p.m., Location: Fine Hall 314 |
| Abstract: | The notion of a boundary for a non-compact group appears in connection with the theory of harmonic functions on symmetric spaces and the theory of random walks on groups, and also in connection with the study of G-spaces, particularly compact G-spaces. In this lecture we'll recall some of the basic ideas and survey some recent results involving group boundaries due to Zimmer, Nevo, Shalom, Bader,and Kaimanovich. |
| Special Arithmetic Geometry and Number Theory Conference in Honor of Nicholas M. Katz for his 60th Birthday | |
| Topics and Presenters: | See www.math.princeton.edu/katzconf/index.html for more information |
| Date: | Thursday, December 11, 2003 - Sunday, December 14, 2003 |
| Ergodic Theory and Statistical Mechanics Seminar | |
| Topic: | Janossy densities in determinantal and pfaffian ensembles of random matrices |
| Presenter: | Alexander Soshnikov, University of California at Davis |
| Date: | Thursday, December 11, 2003, Time: 2:00 p.m., Location: Fine Hall 224 |
| Abstract: | In the first part of the talk I plan to give an introduction to detertminantal random point process and discuss some examples. The second part of the talk is devoted to the problem of the calculation of the Janossy densities in some special ensembles of random matrices, including the Laguerre (Wishart) ensemble. |
| Joint Columbia University/Courant Institute/Princeton University Differential Geometry Seminar | |
| Topic: | Collapsing and non-collapsing |
| Presenter: | Jeff Cheeger, Courant Institute |
| Date: | Friday, December 12, 2003, Time: 2:00 p.m., Location: Columbia University, New York |
| Joint Columbia University/Courant Institute/Princeton University Differential Geometry Seminar | |
| Topic: | Extremal K\"ahler metrics and applications |
| Presenter: | Gang Tian, Princeton University |
| Date: | Friday, December 12, 2003, Time: 3:30 p.m., Location: Columbia University, New York |
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