Davide Catania, of the Università degli Studi di Brescia, is visiting the department for two weeks (until 3rd May) funded by a London Mathematical Society grant.  His visit is hosted by Michele Bartuccelli.  Davide’s recent research is on the rigorous nonlinear analysis of problems in fluid dynamics and magneto-hydrodynamics, and his homepage is here. During his visit he will work with Michele on the problem of the lower and upper bounds for the “crest factor” of solutions of the forced Navier-Stokes equations in two space dimensions. The crest factor is defined as the ratio between the sup-norm (the amplitude) of a solution and the spatial average of the square of the same solution. Its value contains very important information on the “distortion” away from the spatial average of any particular solution. It is in fact a standard measurement used in fluid dynamics in real turbulence experiments.  During his visit he will also give a talk at Oxford and Sussex.