## G.O. Hakobyan, V.N. Margaryan Gevrey hypoellipticity for a class of degenerated quasi-elliptic operators

Comment.Math.Univ.Carolinae 44,4 (2003) 637-644.

Abstract:The problems of Gevrey hypoellipticity for a class of degenerated quasi-elliptic operators are studied by several authors (see [1]--[5]). In this paper we obtain the Gevrey hypoellipticity for a degenerated quasi-elliptic operator in \$\Bbb R^2\$, without any restriction on the characteristic polyhedron.

Keywords: Gevrey class, Gevrey hypoellipticity, hypoelliptic operator, degenerated \newline quasi-elliptic operator
AMS Subject Classification: 35B05, 35H10, 35H35