Reverse Inequalities for Subelliptic Functions

V. S. Klimov

Matematičeskie zametki, Tome 111 (2022) no. 4, pp. 525-539

Résumé

We study a wedge $\mathscr{K}(A)$ of solutions of the inequality $A(u) \ge 0$, where $A$ is a linear elliptic operator of order $2m$. For the elements of the wedge, we establish an interior estimate of the form $$ \|u;H_1^{2m}(\omega)\| \le C(\omega,\Omega)\|u;L(\Omega)\|, $$ where $\omega$ is a compact subset of $\Omega$, $H_1^{2 m}(\omega)$ is the Nikol'skii space, $L(\Omega)$ is the Lebesgue space of integrable functions, and the constant $C(\omega,\Omega)$ is independent of the function $u$. Similar estimates that hold up to the boundaries are proved for the functions from $\mathscr{K}(A)$ satisfying the boundary conditions.

Détail

Keywords: wedge, function, elliptic inequality, Banach space.
Mots-clés : norm