Research Highlights

Fractal® Sound Barrier
August 2011The study of the vibrations in domains with boundaries or interfaces of irregular geometry is a complex mathematical problem, for which many questions are still unsolved. Nevertheless, it has been known for a long time that objects of irregular shape or geometry are “bad resonators.” From the seminal work of Bernard Sapoval, a physicist at […]

Galois Representations
August 2011During both terms of the 201011 year, the School of Mathematics held a special program on Galois Representations and Automorphic Forms. The program was organized by the School’s Distinguished Visiting Professor, Richard Taylor of Harvard University. The program had about 33 longterm participants and many other people visited for shorter periods. Six […]

GPS Algorithms
August 2011The Global Positioning System (GPS) is global navigation system consisting of at least twentyfour satellites orbiting in six planes around the earth. GPS is extensively used by both the military and the FAA, with growing applications in civilian markets. The importance of GPS […]

Math Modeling Holds the Key to Manufacturing Breakthroughs
July 2011Many modern manufacturing processes rely on extrusion: either pushing or drawing a thick fluid containing suspended hard particles through a dye to form parts. This process is so complicated that – until now – understanding it has been more of an art form than a science. The way that the material being […]

Multiscale Representation of Macromolecular Motion
May 2011How many variables do we need to describe macromolecular motion? The answer depends on the time and length scale of interest. By analyzing the geometry of the space defined by long molecular dynamics trajectories of macromolecular systems, we find that different regions of the configurational space have different local intrinsic dimension and […]

Secret Identity of Supercharacters
May 2011The AIM workshop “Supercharacters and combinatorial Hopf algebras,” which took place in May 2010, solved one of the open problems in supercharacter theory and resulted in a paper authored by all 28 of the workshop participants. The character theory of pgroups, such as U(n), the group of n x n uppertriangular matrices […]

Inverse Problems and Invisibility
April 2011In inverse problems one probes an object with a particular type of field and measures the response. From these measurements one aims to determine the object’s properties or geometrical structure. Typically, the interaction is restricted to a bounded domain with boundary: a part of the human body, the solid earth, the atmosphere, an airplane, etc. […]

Smoothing Surfaces with Corners
August 2010While visiting the IMA in early 2001, Tom Duchamp of University of Washington, a geometer who works in computer graphics, attended a talk by postdoc Selim Esedoglu on image denoising. He wondered if the denoising method that Esedoglu described, which preserves image edges, could be modified to smooth surfaces that have edges and corners. The […]

It’s All in the Symmetries
August 2010Analytic and Geometric Number Theory The tools used in modern number theory range over many fields from algebra and algebraic geometry to harmonic analysis, representation theory, ergodic theory and combinatorics. Central to the study of many problems concerning prime numbers, diophantine equations and number fields, are sieve methods, Lfunctions (and with these […]

Flipping a Switch
February 2010Fighting TB Might be a Matter of ‘Flipping a Switch’ in Immune Response In the lung, alternatively activated macrophages (AAM) form the first line of defense against microbial infection. Due to the noninflammatory nature of AAM, the lung can be considered as an immunosuppressive organ for respiratory pathogens. However, as infection progresses […]