Global Smoothing for the Periodic KdV Evolution

Burak Erdogan, Nikolaos Tzirakis

The Korteweg-de Vries (KdV) equation with periodic boundary conditions is considered. It is shown that for $H^s$ initial data, $s>-1/2$, and for any $s_1<\min (3s+1,s+1)$, the diffe…