SEPTEMBER 2009 |
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| Algebraic Geometry Seminar |
| Topic: |
Transversality and noncommutative geometry |
| Presenter: |
Susan J. Sierra, Princeton University |
| Date: |
Tuesday, September 15, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
| Abstract: |
Birationally commutative graded algebras solve the moduli problem for "point modules" over a graded ring. They have been a fruitful source of counterexamples, examples, and intuition in noncommutative ring theory. We investigate when a large subclass of birationally commutative algebras is noetherian. Formally, these are idealizer subrings of twisted homogeneous coordinate rings. In the process, we give a (purely algebro-geometric) generalization of the Kleiman-Bertini theorem. |
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| Differential Geometry and Geometric Analysis Seminar |
| Topic: |
CMC foliations on alomost Fuchsian 3-manifolds |
| Presenter: |
Biao Wang, Toledo |
| Date: |
Friday, September 18, 2009, Time: 3:00 p.m., Location: Fine Hall 314 |
| Abstract: |
An alomost Fuchsian 3-manifold is a quasi-Fuchsian 3-manifold that contains an incompressible surface with principal curvatures in (-1,1). In this talk, we will show that any alomost Fuchsian 3-manifold admits a CMC foliation. |
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| Special Seminar |
| Topic: |
Affine deformations of a three-holed sphere |
| Presenter: |
Bill Goldman, University of Maryland |
| Date: |
Tuesday, September 22, 2009, Time: 12:00 p.m., Location: Fine Hall 110 |
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| Discrete Mathematics Seminar |
| Topic: |
Counting flags in digraph |
| Presenter: |
Sergey Norin, Princeton University |
| Date: |
Thursday, September 24, 2009, Time: 2:15 p.m., Location: Fine Hall 224 |
| Abstract: |
Many results in asymptotic extremal combinatorics are obtained using just a handful of instruments, such as induction and Cauchy-Schwarz inequality. The ingenuity lies in combining these tools in just the right way. Recently, Razborov developed a flag calculus which captures many of the available techniques in pure form, and allows one, in particular, to computerize the search for the right combination.
In this talk we outline the general approach and describe its application to two problems in extremal digraph theory. We show that an n vertex digraph with minimum outdegree 0.3465n contains a directed triangle, obtaining a new bound in an important special case of the Caccetta-Haggkvist conjecture. We also show that the maximum number of induced directed two-edge paths in an n vertex digraph is n3/15 + o(n3), resolving a conjecture of Thomasse.
Based on joint work with Jan Hladky and Daniel Kral. |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Radu Laza, Stony Brook University |
| Date: |
Tuesday, September 29, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
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| OCTOBER 2009 |
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| Topology Seminar ***Please note special time and location |
| Topic: |
Topologically minimal surfaces in 3-manifolds |
| Presenter: |
David Bachman, Pitzer College |
| Date: |
Thursday, October 1, 2009 Time: 2:00 p.m., Location: Fine Hall 322 |
| Abstract: |
Topologically minimal surfaces are the topological analogue of geometrically minimal surfaces. Such surfaces generalize well known classes, such as incompressible, strongly irreducible (or weakly incompressible), and critical surfaces. Applications include problems dealing with stabilization, amalgamation, and isotopy of Heegaard splittings and bridge spheres for knots. In this talk we will review the basic definitions and discuss both existing and potential applications of this new theory. |
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| Topology Seminar |
| Topic: |
Persistence of Essential Surfaces after Dehn filling |
| Presenter: |
David Bachman, Pitzer College |
| Date: |
Thursday, October 1, 2009 Time: 4:30 p.m., Location: Fine Hall 314 |
| Abstract: |
We show that the set of closed, essential, 2-sided surfaces (considered up to isotopy) in a 3-manifold with a torus boundary component survives unchanged in all suitably generic Dehn fillings. Furthermore, for all but finitely many non-generic fillings, we show that two essential surfaces can only become isotopic in a very constrained way. If time permits, we will also sketch future work on the persistence of the set of Heegaard surfaces after generic Dehn filling. This is joint work with Ryan Derby-Talbot and Eric Sedgwick. |
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| PACM Colloquium |
| Topic: |
Self-organized selectivity in Calcium and Sodium Channels: important biology ready for mathematical analysis |
| Presenter: |
Robert Eisenberg, Rush Medical Center/Chicago and Argonne National Labs |
| Date: |
Monday, October 5, 2009, Time: 4:00 p.m., Location: Fine Hall 214 |
| Abstract: |
Ion channels are irresistible objects for biological study because they are the [nano] �valves of life� controlling an enormous range of biological function, much as transistors control computers. Ion channels are appealing objects for physical investigation because conformation changes are not involved in channel function, once the channel is open. Open channels are interesting objects for chemical study because they effectively select among chemically similar ions, under unfavorable circumstances. Channels are interesting objects for physical study because they contain an enormous density of charge, fixed, mobile, and induced. Direct simulation of channel behavior in atomic detail is difficult if not impossible, because ion transit takes ~ 10-8 sec compared to a simulation calculation time step of 10-16 sec and a biological time scale beginning at 10-4 sec. Direct simulation must deal with concentrations of 10-7 to 55 M in a single calculation, and macroscopic electric fields and concentration gradients produce substantial flows which are the function of the channel, making equilibrium analysis unhelpful. |
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| Algebraic Geometry Seminar |
| Topic: |
Homotopy Theoretic methods on Chow varieties |
| Presenter: |
Wenchuan Hu, IAS |
| Date: |
Tuesday, October 6, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
| Abstract: |
The homotopy theoretic method has been applied to the algebraic cycle theory for a long period of time. In particular, it can be applied to compute topological invariants of Chow varieties. In this talk I will discuss this method in calculating the Euler Characteristic of Chow varieties. The calculation in a direct and simple way (this result has been obtained by Blaine Lawson and Stephen Yau in a different way). This technique also can be applied to Chow varieties with certain group actions and other cases. Furthermore, I will also talk about the application of the method on l-adic Euler-Poincare Characteristic of Chow varieties over arbitrary algebraic closed field. |
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| Joint IAS/Princeton University Number Theory Seminar |
| Topic: |
An arithmetic fundamental lemma for unitary group of three variable |
| Presenter: |
Wei Zhang, Harvard |
| Date: |
Thursday, October 8, 2009, Time: 4:30 p.m., Location: Fine Hall 214 |
| Abstract: |
In this talk I'll present a relative trace formula approach to the Gross-Zagier formula and its high dimensional generalization (a derivative version of the global Gross-Prasad conjecture) for unitary group. In particular, an arithmetic fundamental lemma (AFL) is proposed. Some results proved recently will be presented, including the AFL for unitary group of three variable. |
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| Topology Seminar |
| Topic: |
TBA |
| Presenter: |
Andras Stipsicz, Renyi Institute, Hungary |
| Date: |
Thursday, October 8, 2009, Time: 4:30 p.m., Location: Fine Hall 314 |
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| PACM Colloquium (Joint with Analysis Seminar) |
| Topic: |
Harmonic Analysis and Geometries of Digital Data Bases |
| Presenter: |
Raphy Coifman, Yale University |
| Date: |
Monday, October 12, 2009, Time: 4:00 p.m., Location: Fine Hall 214 |
| Abstract: |
Given a matrix (of Data) we describe methodologies to build two multiscale (inference) Geometries/Harmonic Analysis one on the rows , the other on the columns . The geometries are designed to simplify the representation of the data base . We will provide a number of examples including; matrices of operators , psychological questionnaires, vector valued images, scientific articles, etc. In all these cases tensor Haar orthogonal bases play a crucial role in organizing the data base viewed as a function of two variables (row, column) in the case of potential operators we relate to Calderon Zugmund decompositions , while for other data this is a "data agnostic analytic learning tool" For the example of the matrix of eigenfunctions of a discretized Laplace operator ( say, on a compact manifold) we obtain both the Geometry of the domain of the Laplace operator as well as a dual multiscale Geometry of the eigenvectors... |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Jong Hae Keum, KIAS |
| Date: |
Tuesday, October 13, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
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| Differential Geometry and Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Marcus Khuri, SUNY Stony Brook |
| Date: |
Friday, October 16, 2009, Time: 3:00 p.m., Location: Fine Hall 314 |
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| Algebraic Geometry Seminar |
| Topic: |
Algebraic curves with CM |
| Presenter: |
Frans Oort, University of Utrecht |
| Date: |
Tuesday, October 20, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
| Abstract: |
Is every abelian variety isogenous with the Jacobian of an algebraic curve? We will study also several other questions in arithmetic geometry and show various implications. We will mention some solutions to these problems. |
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| Discrete Mathematics Seminar |
| Topic: |
TBA |
| Presenter: |
Wesley Pegden, Rutgers University |
| Date: |
Thursday, October 22, 2009, Time: 2:15 p.m., Location: Fine Hall 224 |
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| Differential Geometry and Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Sophie Chen, IAS |
| Date: |
Friday, October 23, 2009, Time: 3:00 p.m., Location: Fine Hall 314 |
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| Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Kyril Tintarev, Uppsala University |
| Date: |
Monday, October 26, 2009, Time: 4:00 p.m., Location: Fine Hall 110 |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Mihnea Popa, UIC |
| Date: |
Tuesday, October 27, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
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| Discrete Mathematics Seminar |
| Topic: |
TBA |
| Presenter: |
Julia Wolf, Rutgers University |
| Date: |
Thursday, October 29, 2009, Time: 2:15 p.m., Location: Fine Hall 224 |
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| NOVEMBER 2009 |
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| PACM Colloquium |
| Topic: |
Geometry and Analysis of point sets in high dimensions |
| Presenter: |
Mauro Maggioni, Duke University |
| Date: |
Monday, November 9, 2009, Time: 4:00 p.m., Location: Fine Hall 214 |
| Abstract: |
The analysis of high dimensional data sets is useful in a large variety of applications, from machine learning to dynamical systems: data sets are often modeled as low-dimensional, noisy data sets embedded in high-dimensional spaces; dynamical systems often have very high-dimensional state spaces but sometimes interesting dynamics occurs on low-dimensional sets. We discuss several problems associated with the analysis of the geometry of such sets, and with the approximation of functions on such sets, together with some solutions: in particular we discuss how to construct random walks on such data sets and perform multiscale analysis of them and their applications (especially to machine learning); how to construct robust coordinate systems for data sets; how to estimate reliably the intrinsic dimensionality of the data when only few noisy samples are available. |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Matt DeLand, Stony Brook University |
| Date: |
Tuesday, November 10, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
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| Discrete Mathematics Seminar |
| Topic: |
TBA |
| Presenter: |
Andrew King, Columbia University |
| Date: |
Thursday, November 12, 2009, Time: 2:15 p.m., Location: Fine Hall 224 |
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| Joint Columbia-Courant-PrincetonUniversity Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Vikraman Balaji, Chennai Mathematical Institute
Tony Pantev, University of Pennsylvania |
| Date: |
Friday, November 13, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
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| Differential Geometry and Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Will Wylie, University of Pennsylvania |
| Date: |
Friday, November 13, 2009, Time: 3:00 p.m., Location: Fine Hall 314 |
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| PACM Colloquium |
| Topic: |
TBA |
| Presenter: |
Erik Vanmarcke, Civil and Environmental Engineering |
| Date: |
Monday, November 16, 2009, Time: 4:00 p.m., Location: Fine Hall 214 |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Paul Hacking, University of Massachusetts Amherst |
| Date: |
Tuesday, November 17, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
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| Discrete Mathematics Seminar |
| Topic: |
TBA |
| Presenter: |
Peter Winkler, Dartmouth College |
| Date: |
Thursday, November 19, 2009, Time: 2:15 p.m., Location: Fine Hall 224 |
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| Differential Geometry and Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Martin Li, Courant Institute |
| Date: |
Friday, November 20, 2009, Time: 3:00 p.m., Location: Fine Hall 314 |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Tommase deFernex, University of Utah |
| Date: |
Tuesday, November 24, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
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| PACM Colloquium |
| Topic: |
TBA |
| Presenter: |
Joris Dik, Delft University of Technology, Netherlands |
| Date: |
Monday, November 30, 2009, Time: 4:00 p.m., Location: Fine Hall 214 |
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DECEMBER 2009 |
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| Discrete Mathematics Seminar *** Please note special day |
| Topic: |
TBA |
| Presenter: |
Maria Chudnovsky, Columbia University |
| Date: |
Wednesday, December 2, 2009, Time: 2:15 p.m., Location: Fine Hall 224 |
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| Differential Geometry and Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Christine Breiner, MIT |
| Date: |
Friday, December 4, 2009, Time: 3:00 p.m., Location: Fine Hall 314 |
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| PACM Colloquium |
| Topic: |
Imaging Techniques and the Rejuvenation of Artwork |
| Presenter: |
Roy S. Berns, Munsell Color Science Laboratory, Chester F. Carlson Center for Imaging Science, Rochester Institute of Technology, USA |
| Date: |
Monday, December 7, 2009, Time: 4:00 p.m., Location: Fine Hall 214 |
| Abstract: |
Advances in digital imaging within the visible spectrum enable the accurate color rendering of artwork. It is possible to generate a colorimetric image with high spatial resolution and high image quality (appropriate sharpness and low noise). When the number of sensor channels exceeds three, it is also possible to generate spectral images. Spectral images can be used to calculate colorimetric images for any illuminant and observer pair, to evaluate color inconstancy, as an aid in retouching (i.e., �restorative inpainting�), for pigment mapping, and to improve printed reproductions. These digital images, of course, record the color and spectra of the artwork in its current condition. Depending on how the artwork has aged, its color may bear little resemblance to its appearance when first executed. This can dramatically affect the analysis of the painting in terms of its historical context and understanding the artist�s working methods. A variety of techniques can be used to determine such color changes including analysing cross-sections, finding protected areas and identical materials that retain their color, early photographic records, and descriptions by art critics and connoisseurs at the time of creation. Having determined that a color change has occurred, it is possible to �rejuvenate� the colors of a digital image by using the principles of instrumental-based color matching. These principles are used to determine pigments and their concentrations that when mixed, match a particular color. This is equivalent to pigment mapping. The digital rejuvenation is performed by either replacing the spectral properties of the changed pigment with one that hasn�t changed or increasing the concentration of a pigment that has faded. These rejuvenated images, while speculative, provide important and interesting new insights. This presentation will review research by the author in digital rejuvenation using examples by Vincent Van Gogh and Georges Seurat. |
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| Algebraic Geometry Seminar |
| Topic: |
TBA |
| Presenter: |
Roya Beheshti Zavareh, Washington University in St. Louis |
| Date: |
Tuesday, December 8, 2009, Time: 4:30 p.m., Location: Fine Hall 322 |
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| Differential Geometry and Geometric Analysis Seminar |
| Topic: |
TBA |
| Presenter: |
Song Sun, Wisconsin |
| Date: |
Friday, December 11, 2009, Time: 3:00 p.m., Location: Fine Hall 314 |
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