3 papers
math.DG2001
Q-Curvature and Poincare Metrics
Charles Fefferman, C. Robin Graham
This article presents a new definition of Branson's Q-curvature in even-dimensional conformal geometry. We derive the Q-curvature as a coefficient in the asymptotic expansion of th…
math.AP2001
Scalars convected by a 2D incompressible flow
Diego Cordoba, Charles Fefferman
We provide a test for numerical simulations, for several two dimensional incompressible flows, that appear to develop sharp fronts. We show that in order to have a front the veloci…
math.AP2001
Growth of solutions for QG and 2D Euler equations
Diego Cordoba, Charles Fefferman
We study the rate of growth of sharp fronts of the Quasi-geostrophic equation and 2D incompressible Euler equations.. The development of sharp fronts are due to a mechanism that pi…