Cartan determinant conjecture
Determine whether the Cartan determinant of a finite-dimensional algebra of finite global dimension can equal -1, or equivalently whether the Cartan determinant is necessarily 1.
References
It is a major open problem, called the Cartan determinant conjecture, whether the Cartan determinant can be -1 or not, see [FZ] and [Z].
— Auslander regular algebras and Coxeter matrices
(2501.09447 - Klász et al., 16 Jan 2025) in Section 1, immediately before Corollary 1.3