STABILITY OF AFFINE G-VARIETIES AND IRREDUCIBILITY IN REDUCTIVE GROUPS
STABILITY OF AFFINE G-VARIETIES AND IRREDUCIBILITY IN REDUCTIVE GROUPS
Let $G$ be a reductive affine algebraic group, and let $X$ be an affine algebraic $G$-variety. We establish a (poly)stability criterion for points $x\in X$ in terms of intrinsically defined closed subgroups $H_{x}$ of $G$, and relate it with the numerical criterion of Mumford, and with Richardson and Bate-Martin-Röhrle criteria, …