Computing isolated orbifolds in weighted flag varieties

TL;DR

This paper introduces an algorithm to classify projectively Gorenstein n-folds with isolated orbifold points within weighted flag varieties, and applies it to construct specific 3-folds in weighted G2 varieties.

Contribution

The authors develop a novel algorithm for computing Gorenstein n-folds with orbifold points in weighted flag varieties and demonstrate its application to explicit 3-fold constructions.

Findings

Classified polarized 3-folds with orbifold points in weighted G2 varieties.

Constructed families of log-terminal Q-Fano 3-folds explicitly.

Provided new examples of orbifold structures in weighted flag varieties.

Abstract

Given a weighted flag variety $w\Sigma(\mu,u)$ corresponding to chosen fixed parameters $\mu$ and $u$, we present an algorithm to compute lists of all possible projectively Gorenstein $n$-folds, having canonical weight $k$ and isolated orbifold points, appearing as weighted complete intersections in $w\Sigma(\mu,u) $ or some projective cone(s) over $w\Sigma(\mu,u)$. We apply our algorithm to compute lists of interesting classes of polarized 3-folds with isolated orbifold points in the codimension 8 weighted $G_2$ variety. We also show the existence of some families of log-terminal $\mathbb Q$-Fano 3-folds in codimension 8 by explicitly constructing them as quasilinear sections of a weighted $G_2$-variety.