Space-time decay of Navier-Stokes flows invariant under rotations
Résumé
We show that the solutions to the non-stationary Navier-Stokesequations in $R^d$, $d=2,3$ which are left invariant under the actionof discrete subgroups of the orthogonal group $O(d)$ decay muchfaster as $|x|\to\infty$ or $ t \to\infty$ than in the generic case and wecompute, for each subgroup, the precise decay rates in space-timeof the velocity field.