Problems / algebra
algebra / Representation theory of algebras; homological conjectures
The Nakayama conjecture on dominant dimension
Claims Corollary 1.2: for the symmetric pair (A,M) of the Tachikawa counterexample and every field extension K of F2(q,H1,H2), the finite-dimensional algebra ΓK=End(AK⊕MK)op has all injective terms projective but infinite self-injective dimension, has a nonzero simple S with Exti(S,ΓK)=0 for all i≥0, and has a projective-injective Wakamatsu tilting module that is not tilting. Hence the classical, generalized and strong Nakayama conjectures, the Auslander-Gorenstein conjecture and the Wakamatsu tilting conjecture all fail. Corollary 1.3: ΓK has infinite little and big finitistic dimension. It does NOT give characteristic-zero examples.