seminarspring2002

DATE	SEMINAR	TIME	ROOM	SPEAKER	TITLE
Thur Jan. 31	Algebra	1:30-2:30	RH 222	Jim Riles	Working Seminar on Bergman's paper.
Tue Feb. 5	SLU Math & CS Club	4:10-5:10	RH 237	Charles Ford	Monstrous Moonshine
Abstract: Sponsored by the SLU Math and CS Club: The work of Evariste Galois (1811-1832) on fifth degree polynomials initiated a study of finite group theory that resulted, in 1980, in the classification of its "building blocks". This talk focuses on the discoveries made at the culmination of this effort: a group so unusual that is has been dubbed "The Monster" and connections to other branches of mathematics so unexpected that they have been labeled "Moonshine".
Thur. Feb 7	Algebra	1:10-2:30	RH 222	Sandra Spiroff Univ. of Illinois, Champaigne-Urbana	"Limiting Behaviour on Restrictions of Divisor Classes to Hypersurfaces"
Abstract: We investigate the injectivity of the canonical map of divisor class j_n*: Cl(A) --> Cl(A / f_nA)for a sequence of prime elements f_n lying in successively higher powers of the maximal ideal m. We show that no non-trivial divisor class can lie in every kernel.
Fri. Feb. 8	Topology/ Geometry	4:10-5:00	RH 128	Dr. David Letscher Oklahoma State University	"Computational Complexity of Knot Theory and 3-Manifold Algorithms"
Abstract: Among the most fundamental questions in mathematics is whether you can decide if two objects are the same. In 1961 Haken constructed an algorithm to decide if a knot is unknotted. Recent work of Hass, Lagarias and others has analyzed this algorithm to decide its computational complexity. Their results show that the unknot can be recognized in exponential time and also that the unknot recognition problem is both in NP and co-NP. A number of other problems in knot theory and 3-manifold topology are also known to be solvable. These include deciding if two knots are isotopic, 3-sphere recognition and for some classes of 3-manifolds deciding if two manifolds are homeomorphic. The computational complexity of these algorithms and others will be discussed. Also, practical implementations of these algorithms and the software package REGINA will be talked about.
Tues. Feb 12	Analysis	4:10-5:00	RH 237	Brody Johnson Washington University	"Wavelets, Oversampling, and Applications"
Abstract: We will begin with a brief introduction to wavelet theory in the classical context of one dimension. With this motivation we will proceed to consider the problem of bound-preserving oversampling for wavelet frames in n dimensions, presenting a result that generalizes the work of Chui and Shi to the matrix oversampling case. This main result, the so-called Second Oversampling Theorem, describes certain admissibility conditions for an oversampling matrix that guarantee preservation of the frame bounds under oversampling. We will pause to give examples of admissable oversampling matrices for common dilation matrices. We will then discuss a related problem in which the compatibility of oversampling with multiresolution analysis is addressed. We will see that admissable oversampling matrices, in fact, preserve the multiresolution structure and also endow the oversampled system with a discrete wavelet transform. We will conclude with a presentation of numerical examples that illustrate the oversampling effect, commenting on the utility of such systems in applications.
Thur. Feb. 14	Algebra	1:30-2:30	RH 222	Jim Riles	Working Seminar on Bergman's paper.
Thur. Feb. 14	Topology/ Geometry	4:10-5:00	RH 237	Dr. Eugene Xia University of Massachusetts, Amherst	"Higgs Bundles on Riemann Surfaces"
Abstract: We construct Higgs bundles on a Riemann surface and describe how the moduli of Higgs bundles relates to the representation variety of the surface. The talk will present the main structure of the theory by using the abelian Hodge theory as examples for exposition. Applications include the study of the topology of the representation varieties of Riemann surfaces.
Tue Feb. 19	Topology/ Geometry	3:30-4:30	RH 142	Dr. John Bryden Univ. of Illinois, Edwardsville	(1) An introduction to Topological Quantum Field Theory.
Wedn. Feb 20	Algebra	4:10-5:00	RH 237	Dr. D.Reed Solomon	Computability theoretic aspects of ordered algebraic structures
Abstract: Over the last fifty years, computability theorists have developed powerful methods for studying computational properties of sets of natural numbers. Many of these methods can be applied in more general classes of algebraic structures, giving rise to a field known as effective algebra. In this talk, I will discuss several major themes in effective algebra, including computable presentations, algorithmic dimension, and, if time, the representation of Pi^0_1 classes. Each theme will be illustrated by recent work in a class of ordered algebraic structures.
Tue Feb. 26	Topology/ Geometry	3:30-4:30	RH 142	Dr. John Bryden Univ. of Illinois, Edwardsville	(2) Lessons from Stable Homotopy Theory
Tue Mar. 5	Topology/ Geometry	3:30-4:30	RH 142	Dr. John Bryden Univ. of Illinois, Edwardsville	(3) Topological Quantum Field Theories Arising from Spectral Colorings of Ribbon Graphs.
Tue Mar. 12	Topology/ Geometry	3:30-4:30	RH 142	Dr. John Bryden Univ. of Illinois, Edwardsville	(4) Topological Quantum Field Theories, Cont'd
Tue Mar. 19	Topology/ Geometry	3:30-4:30	RH 142	Christine Bussman	A Topology for any Group as a Quotient of a Free Group (I)
Abstract: Any free group can by given a non-discrete Hausdorff topology by a method exhibited by Marshall Hall, drawing on results by K. Iwasawa. Any group can be expressed as the quotient of a free group by a normal subgroup of that free group, so the topology which Hall imposes on the free group also provides a quotient topology on the selected group. We will first follow Hall's construction of the topology for the free group. Then we will relate group theoretical properties of that normal subgroup of the free group to properties of the quotient topology.
Thur. March 21	Algebra	1:30-2:30	RH 222	Jim Riles	Working Seminar on Bergman's paper.
Tue Mar. 26	Topology/ Geometry	3:30-4:30	RH 142	Christine Bussman	A Topology for any Group as a Quotient of a Free Group (II)
Thur. March 28	Algebra	1:30-2:30	RH 222	Jim Riles	Working Seminar on Bergman's paper.
Mon. April 8	SLU Math & CS Club	3:30-4:30	RH 222	Kevin Scannell	Global Software
Abstract: Learn about the notions of "Internationalization" and Localization" of software and some basic techniques for achieving these goals.
Thur. April 11	Algebra	10:00-11:00	RH 134	Dr. Wenhua Zhao Washington University	D-Log and Formal Flow of Analytic Maps
Thur. April 11	Algebra	1:30-2:30	RH 222	Jim Riles	Working Seminar on Bergman's paper.
Thur. April 18	Algebra	1:30-2:30	RH 222	Jim Riles	Working Seminar on Bergman's paper.
Thur. April 25	Algebra	1:30-2:30	RH 222	Jim Riles	Working Seminar on Bergman's paper.
Fri. April 26	Topology/ Geometry	11:00-12:00	RH 316	Dr. Colin Adams Williams College	"Immersed Surfaces in Hyperbolic 3-Manifolds"
Abstract: We will see how immersed surfaces yield interesting restrictions on the hyperbolic structure of a hyperbolic 3-manifold. In particular, we will see how every closed 3-manifold contains a hyperbolic knot, the complement of which has maximal cusp volume no larger than 9. Hyperbolic 3-manifolds and all the other words appearing in this abstract will be explained in the talk.
Fri. April 26	Colloquium	3:10-5:00	Kelly Auditorium	Mel Slugbate (Dr. Colin Adams Williams College)	Real Estate in Hyperbolic Space: Investment Opportunities for the New Millenium
Abstract: Have you found the new investment climate a bit on the chilly side? Nervous about stocks, bonds and mutual funds? Afraid of risky investments in Euclidean space? Then real estate in hyperbolic space is for you! We will discuss the enormous potential of this new investment opportunity and describe the many fascinating properties of hyperbolic space that make it such an attractive place to live. This is the financial equivalent of the 1980's junk bond. Don't miss it. Bring your checkbook and credit references! No previous math or real estate background assumed! Recommended for students and faculty alike! Roger Ebert says, "Two fingers up!" Mel Slugbate is a Real Estate Broker from Slugbate and Mossbutter Real Estate Agency. (Sponsored by his brother-in-law, Colin Adams, Williams College)
Fri. May 10	Topology/ Geometry	3:00-4:00	RH 142	Dr. Cho	TBA