Two University of California, Davis, faculty researchers have been honored nationally with Alfred P. Sloan Research Fellowships. Each receives one of the two-year, $40,000 awards, which are given in support of outstanding researchers early in their academic careers. Assistant professor of mathematics Steve Shkoller, 31, came to UC Davis in 1999. His research uses geometric techniques to study problems in fluid mechanics, particularly one long-standing problem: developing mathematical models of hydrodynamic problems that can be solved by computer programs. His work is contributing to the understanding of turbulence, one of science's great unsolved problems. Hydrodynamic models could have a wide range of applications, such as weather prediction, aircraft design, and studies of biological and chemical systems. The main difficulty in developing them is that a continuum of spatial scales exists in nature, but only a finite number of scales can be modeled on a computer. Moreover, the smallest scale that even a supercomputer can handle is typically still a great deal larger than the spatial scales where interesting fluid motion may be occurring. By studying the geometry of certain infinite-dimensional spaces called volume-preserving diffeomorphism groups, Shkoller has developed such models, proved the existence and uniqueness of their solutions, and developed new numerical algorithms that are able to preserve fundamental conservation laws. Assistant professor of physics James Wells, 33, also came to UC Davis in 1999. His primary research goal is to understand why particles have mass. For every idea that explains mass, there are predictions for new and unusual behavior of the elementary particles (quarks, leptons, neutrinos, etc.) in collisions at extremely high energies. For example, one idea, called supersymmetry, solves many of the problems of making a self-consistent theory of mass; however, it predicts a large number of new particles and interactions that are only visible at extremely high energies, well above what we experience in ordinary life. Wells has played a leading role in making predictions for what will be seen in high-energy collisions if supersymmetry is a correct description of nature. The Sloan fellowship program grants 100 awards annually in seven fields -- chemistry, computer science, economics, pure and applied mathematics, neuroscience and physics. It began in 1955 as a means of encouraging research by young scholars at a critical time in their careers when other support may be difficult to obtain. Twenty-one past Sloan Fellows have won Nobel Prizes.