Abstract
We introduce and study the notion of \(G\) -coregularity of algebraic varieties endowed with an action of a finite group \(G\) . We compute the \(G\) -coregularity of smooth del Pezzo surfaces of degree at least \(6\) , and give a characterization of groups that can act on conic bundles with \(G\) -coregularity \(0\) . We describe the relations between the notions of \(G\) -coregularity, \(G\) -log canonical thresholds, \(G\) -birational rigidity, and exceptional quotient singularities.