Frobenius--Perron dimension via $τ$-tilting theory
Takahide Adachi, Ryoichi Kase
TL;DR
This work develops a combinatorial framework tying the Frobenius–Perron dimension $FPdim$ of finite-dimensional algebras to $ au$-tilting theory and semibricks, yielding finiteness results and precise bounds. It proves a fundamental inequality linking $FPdim(A)$ to the $FPdim$ of the finite lattice $ au$-tiltp$(A)$ and a BR-modulated self-extension parameter $d_b$, with equality when $d_b=0$. The authors establish sharp bounds for $ au$-tilting finite algebras of tame representation type and give exact $FPdim$ values for Nakayama algebras (0 or 1) and generalized preprojective algebras of Dynkin type (equal to the spectral radius $ ho(Q)$ of the Gabriel quiver), supported by Coxeter-theoretic and lattice-combinatorial methods. Collectively, the results illuminate how representation-type and lattice structure govern $FPdim$, provide explicit computations for central algebra families, and furnish a toolkit for further FPdim determinations in related settings.
Abstract
From the perspective of $τ$-tilting theory, we study Frobenius--Perron dimensions of finite-dimensional algebras. First, we evaluate the Frobenius--Perron dimensions of $τ$-tilting finite algebras by a combinatorial method in $τ$-tilting theory. Secondly, we give the upper bound for the Frobenius--Perron dimension for $τ$-tilting finite algebras of tame representation type. Thirdly, we determine the Frobenius--Perron dimensions of Nakayama algebras and generalized preprojective algebras of Dynkin type in the sense of Geiss--Leclerc--Schröer.
