Title: The Steinberg linkage class for a reductive algebraic group,
Abstract: Let G be a reductive algebraic group over a field of positive characteristic
and denote by C(G) the category of rational G-modules. In this note we
investigate the subcategory of C(G) consisting of those modules whose
composition factors all have highest weights linked to the Steinberg weight.
This subcategory is denoted ST and called the Steinberg component. We give an
explicit equivalence between ST and C(G) and we derive some consequences. In
particular, our result allows us to relate the Frobenius contracting functor to
the projection functor from C(G) onto ST .