Line bundles on fantastacks and their cohomology. (2026)
Abstract
Let $\mathcal{F}_{\Sigma,\beta}$ be a fantastack determined by $\beta \colon \mathbb{Z}^n \to N$ and a fan $\Sigma \subseteq N_{\mathbb R}$, and $\mathscr{L}$ be a line bundle. We construct a fan $\Sigma'$ and a torus-invariant Cartier divisor $D'$ such that for all $i \geq 0$, we have
\[
H^i(\mathcal{F}_{\Sigma,\beta},\mathscr{L}) \cong H^i(X_{\Sigma'}, \mathscr O(D')).
\]