Published online by Cambridge University Press: 27 October 2021
Let $\mathscr{C}$ be a
$(d+2)$-angulated category with d-suspension functor
$\Sigma^d$. Our main results show that every Serre functor on
$\mathscr{C}$ is a
$(d+2)$-angulated functor. We also show that
$\mathscr{C}$ has a Serre functor
$\mathbb{S}$ if and only if
$\mathscr{C}$ has Auslander–Reiten
$(d+2)$-angles. Moreover,
$\tau_d=\mathbb{S}\Sigma^{-d}$ where
$\tau_d$ is d-Auslander–Reiten translation. These results generalize work by Bondal–Kapranov and Reiten–Van den Bergh. As an application, we prove that for a strongly functorially finite subcategory
$\mathscr{X}$ of
$\mathscr{C}$, the quotient category
$\mathscr{C}/\mathscr{X}$ is a
$(d+2)$-angulated category if and only if
$(\mathscr{C},\mathscr{C})$ is an
$\mathscr{X}$-mutation pair, and if and only if
$\tau_d\mathscr{X} =\mathscr{X}$.
This work was supported by the Scientific Research Fund of Hunan Provincial Education Department (Grant No. 19B239) and the National Natural Science Foundation of China (Grant No. 11901190).