Monday January 22, 2007

DE and Applied/Computational Math Seminar

TIME: 3:35 p.m. -­ 4:25 p.m.
ROOM: Ayres Hall 309A
SPEAKER: Dr. Phil Ferguson, ORNL
TITLE: Neutron Source Development at the Spallation Neutron Source

ABSTRACT: The Spallation Neutron Source (SNS), which completed commissioning in April 2006, will become the world's highest power pulsed spallation neutron source during the process of achieving the planned beam power of 1.4 MW. The system was design for world-class performance, featuring a flowing mercury target, a beryllium reflector, three supercritical hydrogen moderators, and an ambient water moderator. The purpose of the Neutron Source Development Group is to enhance the current and future target systems through improvements in reliability, maintainability, and system performance. Current efforts within the Neutron Source Development Group will be discussed, including mercury target development, enhancements for the next SNS reflector, and initial concepts for a second SNS target station.

Computational Topology Seminar

TIME: 10:10a.m. -11:00a.m.
ROOM: Ayres Hall 015
SPEAKER: Jerzy Dydak
TITLE: Computation of the fundamental group of mapping spaces.
ABSTRACT: We will have an organizational meeting first followed by the talk.

Wednesday January 24, 2007

Algebra Seminar

TIME: 3:35 p.m. -­ 4:25 p.m.
ROOM: Ayres Hall 309B
SPEAKER: Professor David Anderson
The topic this semester will be an introduction to homological algebra. This should be of particular interest to students in algebra or topology. The only prerequisite is some knowledge of module theory (as in Math 552). The first several meetings will be lectures by Professor Anderson.

Computational Topology Seminar

TIME: 10:10a.m. -11:00a.m.
ROOM: Ayres Hall 015
SPEAKER: Jerzy Dydak
TITLE: Computation of the fundamental group of mapping spaces.

Colloquium

TIME: 3:35 p.m. -­ 4:25 p.m.
ROOM: Ayres Hall 214
SPEAKER: Dr. Brett Wick, Candidate for the position of Assistant Professor in Analysis
TITLE: Multiparameter Riesz Commutators
ABSTRACT: An important question in analysis is to determine the behavior of an operator associated to a symbol purely from data about the symbol. For example, a multiplication operator is bounded if and only if the symbol is bounded. We will be interested in determining necessary and sufficient conditions on the symbol which will imply that a commutator between a multiplication operator and a singular integral operator is bounded. This commutation allows for cancellation to play a role and is a significant feature in determining conditions on the symbol.

In addition to the history behind this problem, connections with real and complex analysis in one and several variables and interpretations of these results in operator theory and function theory will be highlighted. Finally, recent results will be discussed.

Friday January 26, 2007

Colloquium

TIME: 3:35 p.m. -­ 4:25 p.m.
ROOM: Ayres Hall 214
SPEAKER: Yekaterina Epshteyn, candidate for the position of Assistant
Professor in Computational and Applied Mathematics
TITLE: hp Discontinuous Galerkin Finite Element Methods For Incompressible
Two-Phase Flow Models in Porous Media
ABSTRACT: There is a need for efficient and accurate numerical methods for solving multiphase flow problems. In this talk, we show that high order discontinuous Galerkin methods are promising candidates. In particular, we consider two different formulations of the incompressible two-phase flow problems arising in porous media: "phase-pressure, phase-saturation" formulation and "global pressure, phase-saturation" formulation. We introduce implicit, fully coupled $hp$-schemes based on discontinuous Galerkin methods to solve numerically the two-phase flow problem. Numerical analysis (existence of the discrete solution, convergence) of the introduced schemes and simulations of the two-phase flow in homogeneous and heterogeneous media are presented.

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