I'm a general theoretical physicist and applied mathematician, and am interested in many kinds of mathematical modeling. My current research focuses on stochastic modeling (noise models, random fluctuation theory) and the limiting properties of stochastic models, such as the way that activation by weak noise occurs. Applications are in statistical physics, chemical physics, and in noise-perturbed dynamical systems generally (e.g., in noisy electronic circuits). I'm also interested in quantum-mechanical WKB theory and in geometrical optics. The unifying theoretical concept is the concept of a semiclassical limit, which may be a weak-noise limit, a small-hbar limit, or a small-wavelength limit.