The Weyl extension algebra of $G{L}_2({\bar{\mathbb{F}}}_p)$

Abstract

We compute the Yoneda extension algebra of the collection of Weyl modules for $G{L}_2$ over an algebraically closed field of positive characteristic p by developing a theory of generalised Koszul duality for certain 2-functors, one of which controls the rational representation theory of $G{L}_2$ over such a field.

arXiv comment55 pages, Adv. Math. 246 (2013), 144-197; this new version corrects a mistake in Lemma 3 by adding a new Appendix to replace Section 5

References in corpus (2)

• Koszul dual 2-functors and extension algebras of simple modules for $G{L}_2$
• On a common generalization of Koszul duality and tilting equivalence

Cited by in corpus (4)

• Quasi-hereditary algebras and generalized Koszul duality
• Some Homological Properties of Tensor and Wreath Products of Quasi-hereditary Algebras
• Dimensions of Ext-groups of Weyl modules for GL_2
• Hochschild cohomology of polynomial representations of $G{L}_2({\bar{\mathbb{F}}}_p)$