On the growth of Sobolev norm for the cubic NLS on two dimensional product space

Abstract

We obtain polynomial bounds on the growth in time of Sobolev norm of solutions to the cubic defocussing nonlinear Schrödinger equation on two dimensional product space. We also give the angular improved bilinear Strichartz estimates for frequency localized functions, which estimates are used for enhancement of a smoothing estimates. Such upper bounds for the growth of Sobolev norms measure the transfer of energy from low to high modes as time grows on.