English

Counterexamples to the Tilting and $(p,r)$-Filtration Conjectures

Representation Theory 2019-02-20 v2

Abstract

In this paper the authors produce a projective indecomposable module for the Frobenius kernel of a simple algebraic group in characteristic pp that is not the restriction of an indecomposable tilting module. This yields a counterexample to Donkin's longstanding Tilting Module Conjecture. The authors also produce a Weyl module that does not admit a pp-Weyl filtration. This answers an old question of Jantzen, and also provides a counterexample to the (p,r)(p,r)-Filtration Conjecture.

Keywords

Cite

@article{arxiv.1901.06687,
  title  = {Counterexamples to the Tilting and $(p,r)$-Filtration Conjectures},
  author = {Christopher P. Bendel and Daniel K. Nakano and Cornelius Pillen and Paul Sobaje},
  journal= {arXiv preprint arXiv:1901.06687},
  year   = {2019}
}