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IMA Newsletter #397

November 2009

2009-2010 Program

See http://www.ima.umn.edu/2009-2010/ for a full description of the 2009-2010 program on Complex Fluids and Complex Flows.

University of Pennsylvania has joined the IMA as a Participating Institution effective October 1, 2009.

2009-2010 IMA Participating Institutions Conferences

IMA Events

Public Lecture

Jeffrey Weeks: The Shape of Space

November 12, 2009

Speakers: Jeffrey Weeks (NONE)
Schedule

Monday, November 2

10:45am-11:15amCoffee breakLind Hall 400
2:30pm-3:20pmTopics in the theory of the Navier-Stokes equationsVladimir Sverak (University of Minnesota)Lind Hall 305

Tuesday, November 3

10:45am-11:15amCoffee breakLind Hall 400
11:15am-12:15pmMathematical models and measures of mixingZhi (George) Lin (University of Minnesota)Lind Hall 305 PS

Wednesday, November 4

10:45am-11:15amCoffee breakLind Hall 400
11:15am-12:15pmOn spider-man and film casting: the mathematics of free liquid fibers and films in elongationThomas C. Hagen (University of Memphis)Lind Hall 305 2009-2010Seminar
2:30pm-3:20pmTopics in the theory of the Navier-Stokes equationsVladimir Sverak (University of Minnesota)Lind Hall 305

Thursday, November 5

10:45am-11:15amCoffee breakLind Hall 400

Friday, November 6

10:45am-11:15amCoffee breakLind Hall 400

Monday, November 9

10:45am-11:15amCoffee breakLind Hall 400
2:30pm-3:20pmTopics in the theory of the Navier-Stokes equationsVladimir Sverak (University of Minnesota)Lind Hall 305

Tuesday, November 10

10:45am-11:15amCoffee breakLind Hall 400
11:15am-12:15pmTurbulent times in flatlandNusret Balci (University of Minnesota)Lind Hall 305 PS

Wednesday, November 11

10:45am-11:15amCoffee breakLind Hall 400
11:15am-12:15pmAre viscoelastic flows under control or out of control?Michael Renardy (Virginia Polytechnic Institute and State University)Lind Hall 305 2009-2010Seminar

Thursday, November 12

10:45am-11:15amCoffee breakLind Hall 400
7:00pm-8:00pm The shape of spaceJeffrey Weeks Willey Hall 175 PUB11.12.09

Friday, November 13

10:45am-11:15amCoffee breakLind Hall 400

Saturday, November 14

Monday, November 16

10:45am-11:15amCoffee breakLind Hall 400
2:30pm-3:20pmTopics in the theory of the Navier-Stokes equationsVladimir Sverak (University of Minnesota)Lind Hall 305

Tuesday, November 17

10:45am-11:15amCoffee breakLind Hall 400
11:15am-12:15pmExperimental determination of the likelihood of catastrophic instability in Gaussian eliminationKara Lee Maki (University of Minnesota)Lind Hall 305 PS

Wednesday, November 18

10:45am-11:15amCoffee breakLind Hall 400
11:15am-12:15pmTurbulence transition in shear flows: what can we learn from pipe flow?Bruno Eckhardt (Philipps-Universität Marburg)Lind Hall 305 2009-2010Seminar
2:30pm-3:20pmTopics in the theory of the Navier-Stokes equationsVladimir Sverak (University of Minnesota)Lind Hall 305

Thursday, November 19

10:45am-11:15amCoffee breakLind Hall 400

Friday, November 20

10:45am-11:15amCoffee breakLind Hall 400

Monday, November 23

2:30pm-3:20pmTopics in the theory of the Navier-Stokes equationsVladimir Sverak (University of Minnesota)Lind Hall 305
3:45pm-4:45pmRichard McLaughlin (University of North Carolina, Chapel Hill) Darwin's theorem, Taylor diffusion, and falling spheres in stratified fluidsVincent Hall 6 AMS

Tuesday, November 24

11:15am-12:15pmThe existence of smooth solutions to fractal Burgers equation with critical exponentChi Hin Chan (University of Minnesota)Lind Hall 305 PS

Thursday, November 26

All DayThanksgiving holiday. The IMA is closed.

Friday, November 27

All DayFloating holiday. The IMA is closed.

Monday, November 30

10:45am-11:15amCoffee breakLind Hall 400
2:30pm-3:20pmTopics in the theory of the Navier-Stokes equationsVladimir Sverak (University of Minnesota)Lind Hall 305
Abstracts
The Sixth Meeting of the Illinois/Missouri Applied Harmonic Analysis Seminar, Saint Louis University, Missouri
Abstract: This one day meeting fosters research interactions among mathematicians, engineers and physicists who develop and apply techniques from harmonic analysis. Theoretical topics of interest include: Fourier analysis, wavelets, Gabor systems (time-frequency analysis), frames, Riesz bases, compressed sensing, approximation theory, X-ray type transforms. Applications of interest include: all kinds of signal and image analysis, processing and reconstruction, both analogue and digital. This conference is supported in part by the Institute for Mathematics and its Applications (IMA) through its Participating Institution (PI) Program. PI members may use IMA/PI funds to support travel of their personnel to this conference. All interested researchers are welcome. There is no registration fee. Travel funding is available for participants based in the U.S. For more information: http://mathcs.slu.edu/~johnson/imaha/
Nusret Balci (University of Minnesota) Turbulent times in flatland
Abstract: We will review the notion of turbulence, present a mathematical theory for it (in 2D), and then see how it can be twisted to have fun with a 3D system (Rayleigh-Benard heat convection problem).
Chi Hin Chan (University of Minnesota) The existence of smooth solutions to fractal Burgers equation with critical exponent
Abstract: In this talk, we present a piece of joint work of Chi Hin Chan and Magdalena Czubak, in which we establish the existence of smooth solutions to fractal Burgers equation with critical exponent by applying the parabolic De Giorgi's method as developed by Luis Caffarelli and Alexis Vasseur. In the talk, we will make a parallel comparison between our work on fractal Burgers' equation with critical exponent and the work by Caffarelli and Vasseur in their paper "Drift diffusion equations with fractional diffusion and the quasi-geostrophic equation.
Bruno Eckhardt (Philipps-Universität Marburg) Turbulence transition in shear flows: what can we learn from pipe flow?
Abstract: According to textbook wisdom, flow down a pipe becomes turbulent near a Reynolds number of about 2000. This simple statement misses many subtleties of the transition: the absence of a linear stability of the laminar flow, the sensitive dependence on perturbations that sometimes succeed and sometimes fail to induce turbulence and the unexpected observation that the turbulent state, once achieved, is not persistent but can decay. All these observations are compatible with the formation of a strange saddle in the state space of the system. I will focus on three aspects: on the appearance of 3-d coherent states, on the information contained in lifetime statistics and on results on the boundary between laminar and turbulent regions. They suggest a generic structuring of state space in flows where turbulent and laminar flow coexist, such as plane Couette flow, Poiseuille flow and perhaps even boundary layers.
Thomas C. Hagen (University of Memphis) On spider-man and film casting: the mathematics of free liquid fibers and films in elongation
Abstract: In this lecture we give an overview of the mathematical theory of free liquid fibers and films of highly viscous liquids in fiber spinning and film casting. The governing equations to be discussed arise as the slender body approximation of the Navier-Stokes equations with moving boundary as 1D or 2D nonlinear coupled hyperbolic-elliptic systems of pdes. Topics of interest in this presentation include existence and uniqueness results, failure of fiber breakup in the purely viscous regime, and spectral determinacy/regularity of the linearized film equations. Some open questions will be motivated.
Zhi (George) Lin (University of Minnesota) Mathematical models and measures of mixing
Abstract: Mixing by stirring can be measured in a variety of ways including tracer particle dispersion, the scalar flux-gradient relationship, or via suppression of scalar density variation in the presence of inhomogeneous sources and sinks. The mixing efficacy of a flow is often expressed in terms of enhanced diffusivity and quantified as an effective diffusion coefficient. In this work we compare and contrast these various notions of effective diffusivity. Via thorough examination of a simple shear flow mixing a scalar sustained by a steady source-sink distribution, we explore apparent inconsistencies and propose a conceptual approach that captures some compatible features of these different models and measures of mixing.
Kara Lee Maki (University of Minnesota) Experimental determination of the likelihood of catastrophic instability in Gaussian elimination
Abstract: The growth factor of a matrix quantifies the amount of potential error growth when a linear system is solved by Gaussian elimination with partial pivoting. While the growth factor has a maximum of 2n-1 for an n × n matrix, experience suggests the occurrence of matrices with exponentially large growth factors is extremely rare. To add computational evidence, we implemented a multicanonical Monte Carlo method to explore the tails of growth factor probability distributions for random matrices.
Michael Renardy (Virginia Polytechnic Institute and State University) Are viscoelastic flows under control or out of control?
Abstract: Controllability refers to the ability to steer a system from a prescribed initial state to a desirable final state. The lecture will give an overview of recent results on the controllability of flows of viscoelastic fluids by means of a prescribed body force or prescribed motion of the boundary.
Vladimir Sverak (University of Minnesota) Topics in the theory of the Navier-Stokes equations
Abstract: The course will cover certain selected topics in the theory of the Navier-Stokes equations. After a brief overview of the main issues of the general theory we will focus on problems in the theory of the steady-state solutions. There are many open problems concerning the steady-state solutions. These problems are presumably easier than the main open questions about the time-dependent equations. Nevertheless, some of them have remained unsolved since their first explicit formulation in the pioneering works of Jean Leray in the 1930s. There is a certain indirect similarity (or "duality") between the mathematical issues raised by these steady-state problems and the issues which come up in connection with the more well-known open problems about the time-dependent equations. In the lectures I hope to cover some of the important results about the steady-state solutions and discuss some of the open problems. The course will be accessible to postdocs and to graduate students with some knowledge of PDEs. For example, an introductory graduate PDE course should be a sufficient prerequisite.
Vladimir Sverak (University of Minnesota) Topics in the theory of the Navier-Stokes equations
Abstract: The course will cover certain selected topics in the theory of the Navier-Stokes equations. After a brief overview of the main issues of the general theory we will focus on problems in the theory of the steady-state solutions. There are many open problems concerning the steady-state solutions. These problems are presumably easier than the main open questions about the time-dependent equations. Nevertheless, some of them have remained unsolved since their first explicit formulation in the pioneering works of Jean Leray in the 1930s. There is a certain indirect similarity (or "duality") between the mathematical issues raised by these steady-state problems and the issues which come up in connection with the more well-known open problems about the time-dependent equations. In the lectures I hope to cover some of the important results about the steady-state solutions and discuss some of the open problems. The course will be accessible to postdocs and to graduate students with some knowledge of PDEs. For example, an introductory graduate PDE course should be a sufficient prerequisite.
Vladimir Sverak (University of Minnesota) Topics in the theory of the Navier-Stokes equations
Abstract: The course will cover certain selected topics in the theory of the Navier-Stokes equations. After a brief overview of the main issues of the general theory we will focus on problems in the theory of the steady-state solutions. There are many open problems concerning the steady-state solutions. These problems are presumably easier than the main open questions about the time-dependent equations. Nevertheless, some of them have remained unsolved since their first explicit formulation in the pioneering works of Jean Leray in the 1930s. There is a certain indirect similarity (or "duality") between the mathematical issues raised by these steady-state problems and the issues which come up in connection with the more well-known open problems about the time-dependent equations. In the lectures I hope to cover some of the important results about the steady-state solutions and discuss some of the open problems. The course will be accessible to postdocs and to graduate students with some knowledge of PDEs. For example, an introductory graduate PDE course should be a sufficient prerequisite.
Vladimir Sverak (University of Minnesota) Topics in the theory of the Navier-Stokes equations
Abstract: The course will cover certain selected topics in the theory of the Navier-Stokes equations. After a brief overview of the main issues of the general theory we will focus on problems in the theory of the steady-state solutions. There are many open problems concerning the steady-state solutions. These problems are presumably easier than the main open questions about the time-dependent equations. Nevertheless, some of them have remained unsolved since their first explicit formulation in the pioneering works of Jean Leray in the 1930s. There is a certain indirect similarity (or "duality") between the mathematical issues raised by these steady-state problems and the issues which come up in connection with the more well-known open problems about the time-dependent equations. In the lectures I hope to cover some of the important results about the steady-state solutions and discuss some of the open problems. The course will be accessible to postdocs and to graduate students with some knowledge of PDEs. For example, an introductory graduate PDE course should be a sufficient prerequisite.
Vladimir Sverak (University of Minnesota) Topics in the theory of the Navier-Stokes equations
Abstract: The course will cover certain selected topics in the theory of the Navier-Stokes equations. After a brief overview of the main issues of the general theory we will focus on problems in the theory of the steady-state solutions. There are many open problems concerning the steady-state solutions. These problems are presumably easier than the main open questions about the time-dependent equations. Nevertheless, some of them have remained unsolved since their first explicit formulation in the pioneering works of Jean Leray in the 1930s. There is a certain indirect similarity (or "duality") between the mathematical issues raised by these steady-state problems and the issues which come up in connection with the more well-known open problems about the time-dependent equations. In the lectures I hope to cover some of the important results about the steady-state solutions and discuss some of the open problems. The course will be accessible to postdocs and to graduate students with some knowledge of PDEs. For example, an introductory graduate PDE course should be a sufficient prerequisite.
Vladimir Sverak (University of Minnesota) Topics in the theory of the Navier-Stokes equations
Abstract: The course will cover certain selected topics in the theory of the Navier-Stokes equations. After a brief overview of the main issues of the general theory we will focus on problems in the theory of the steady-state solutions. There are many open problems concerning the steady-state solutions. These problems are presumably easier than the main open questions about the time-dependent equations. Nevertheless, some of them have remained unsolved since their first explicit formulation in the pioneering works of Jean Leray in the 1930s. There is a certain indirect similarity (or "duality") between the mathematical issues raised by these steady-state problems and the issues which come up in connection with the more well-known open problems about the time-dependent equations. In the lectures I hope to cover some of the important results about the steady-state solutions and discuss some of the open problems. The course will be accessible to postdocs and to graduate students with some knowledge of PDEs. For example, an introductory graduate PDE course should be a sufficient prerequisite.
Jeffrey Weeks The shape of space
Abstract: When we look out on a clear night, the universe seems infinite. Yet this infinity might be an illusion. During the first half of the presentation, computer games will introduce the concept of a "multiconnected universe." Interactive 3D graphics will then take the viewer on a tour of several possible shapes for space. Finally, we'll see how recent satellite data provide tantalizing clues to the true shape of our universe. The only prerequisites for this talk are curiosity and imagination. For middle school and high school students, people interested in astronomy, and all members of the university and surrounding communities.
Visitors in Residence
Nusret Balci University of Minnesota 9/1/2009 - 8/31/2010
Jennifer Beichman University of Michigan 9/1/2009 - 5/31/2010
Richard J. Braun University of Delaware 9/1/2009 - 12/20/2009
Maria-Carme T. Calderer University of Minnesota 9/1/2009 - 6/30/2010
Tamra Carpenter Rutgers University 11/1/2009 - 11/3/2009
Chi Hin Chan University of Minnesota 9/1/2009 - 8/31/2010
Xianjin Chen University of Minnesota 9/1/2008 - 8/31/2010
Eric Choate University of North Carolina 10/10/2009 - 11/10/2009
L. Pamela Cook University of Delaware 9/6/2009 - 12/20/2009
Michael Earl Cromer Jr University of Delaware 9/1/2009 - 12/31/2009
Charles Doering University of Michigan 8/15/2009 - 6/15/2010
Bruno Eckhardt Philipps-Universität Marburg 11/16/2009 - 11/20/2009
Randy H. Ewoldt University of Minnesota 9/1/2009 - 8/31/2010
David Finn Rose-Hulman Institute of Technology 9/1/2009 - 11/23/2009
Sandip Ghosal Northwestern University 9/21/2009 - 12/12/2009
Michael D. Graham University of Wisconsin 9/1/2009 - 12/22/2009
Thomas C. Hagen University of Memphis 9/1/2009 - 12/31/2009
Yunkyong Hyon University of Minnesota 9/1/2008 - 8/31/2010
Mark Iwen University of Minnesota 9/1/2008 - 8/31/2010
Srividhya Jeyaraman University of Minnesota 9/1/2008 - 8/31/2010
Lijian Jiang University of Minnesota 9/10/2008 - 8/31/2010
Mihailo Jovanovic University of Minnesota 9/11/2009 - 6/10/2010
Markus Keel University of Minnesota 7/21/2008 - 6/30/2010
Hyejin Kim University of Minnesota 9/1/2009 - 8/31/2010
Pawel Konieczny University of Minnesota 9/1/2009 - 8/31/2010
Ronald G. Larson University of Michigan 9/12/2009 - 12/22/2009
Chiun-Chang Lee National Taiwan University 10/22/2009 - 6/30/2010
Young-Ju Lee Rutgers University 9/11/2009 - 12/31/2009
Marta Lewicka University of Minnesota 9/1/2009 - 6/30/2010
Yi Li Stevens Institute of Technology 9/16/2009 - 12/17/2009
Yongfeng Li University of Minnesota 9/1/2008 - 8/31/2010
Tai-Chia Lin National Taiwan University 11/29/2009 - 12/10/2009
Zhi (George) Lin University of Minnesota 9/1/2009 - 8/31/2010
Chun Liu University of Minnesota 9/1/2008 - 8/31/2010
Ellen K. Longmire University of Minnesota 9/1/2009 - 6/30/2010
Yasunori Maekawa Kobe University 9/7/2009 - 3/1/2010
Krishnan Mahesh University of Minnesota 9/1/2009 - 6/30/2010
Kara Lee Maki University of Minnesota 9/1/2009 - 8/31/2010
Vasileios Maroulas University of Minnesota 9/1/2008 - 8/31/2010
Yoichiro Mori University of Minnesota 9/1/2009 - 6/30/2010
Walter Morris Rutgers University 11/1/2009 - 11/3/2009
Monika Nitsche University of New Mexico 9/1/2009 - 12/22/2009
Cecilia Ortiz-Duenas University of Minnesota 9/1/2009 - 8/31/2010
Hans G. Othmer University of Minnesota 9/1/2009 - 6/30/2010
Michael Renardy Virginia Polytechnic Institute and State University 9/1/2009 - 12/20/2009
Yuriko Renardy Virginia Polytechnic Institute and State University 9/1/2009 - 12/20/2009
Juan Mario Restrepo University of Arizona 8/11/2009 - 6/15/2010
Rolf Ryham Rice University 11/19/2009 - 11/27/2009
Fadil Santosa University of Minnesota 7/1/2008 - 6/30/2010
Arnd Scheel University of Minnesota 9/1/2009 - 6/30/2010
George R Sell University of Minnesota 9/1/2009 - 6/30/2010
Tsvetanka Sendova University of Minnesota 9/1/2008 - 8/31/2010
Shuanglin Shao University of Minnesota 9/1/2009 - 8/31/2010
Daniel Spirn University of Minnesota 9/8/2009 - 6/1/2010
Paul H. Steen Cornell University 10/15/2009 - 12/15/2009
Panagiotis Stinis University of Minnesota 9/1/2009 - 6/30/2010
Huan Sun Pennsylvania State University 8/16/2009 - 12/15/2009
Vladimir Sverak University of Minnesota 9/1/2009 - 6/30/2010
Mark Taylor Sandia National Laboratories 9/1/2009 - 12/22/2009
Jean-Luc Thiffeault University of Wisconsin 9/1/2009 - 6/30/2010
Chad Michael Topaz Macalester College 9/1/2009 - 6/30/2010
Changyou Wang University of Kentucky 9/1/2009 - 6/15/2010
Jeffrey Weeks NONE 11/11/2009 - 11/13/2009
Sijue Wu University of Michigan 9/1/2009 - 6/5/2010
Wei Xiong University of Minnesota 9/1/2008 - 8/31/2010
Tsuyoshi Yoneda University of Minnesota 9/4/2009 - 8/31/2010
Weigang Zhong University of Minnesota 9/8/2008 - 8/31/2010
Legend: Postdoc or Industrial Postdoc Long-term Visitor

IMA Affiliates:
Arizona State University, Boeing, Corning Incorporated, ExxonMobil, Ford, General Motors, Georgia Institute of Technology, Honeywell, IBM, Indiana University, Iowa State University, Kent State University, Korea Advanced Institute of Science and Technology (KAIST), Lawrence Livermore National Laboratory, Lockheed Martin, Los Alamos National Laboratory, Medtronic, Michigan State University, Michigan Technological University, Microsoft Research, Mississippi State University, Motorola, Northern Illinois University, Ohio State University, Pennsylvania State University, Purdue University, Rice University, Rutgers University, Sandia National Laboratories, Schlumberger Cambridge Research, Schlumberger-Doll, Seoul National University, Siemens, Telcordia, Texas A & M University, University of Central Florida, University of Chicago, University of Cincinnati, University of Delaware, University of Houston, University of Illinois at Urbana-Champaign, University of Iowa, University of Kentucky, University of Maryland, University of Michigan, University of Minnesota, University of Notre Dame, University of Pennsylvania, University of Pittsburgh, University of Tennessee, University of Wisconsin, University of Wyoming, US Air Force Research Laboratory, Wayne State University, Worcester Polytechnic Institute