Klt singularities of horospherical pairs

Boris Pasquier (1)

1 IMAG - Institut Montpelliérain Alexander Grothendieck

Let $X$ be a horospherical $G$-variety and let $D$ be an effective $\mathbb{Q}$-divisor of $X$ that is stable under the action of a Borel subgroup $B$ of $G$ and such that $D+K_X$ is $\mathbb{Q}$-Cartier. We prove, using Bott-Samelson resolutions, that the pair $(X,D)$ is klt if and only if $\lfloor D\rfloor=0$

Mots clés: Bott-Samelson varieties; klt singularities; flag varieties; horospherical varieties

Domaines: Géométrie algébrique [math.AG]

Boris Pasquier. Klt singularities of horospherical pairs. Annales de l'Institut Fourier, 2016, 66 (5), pp.2157-2167. ⟨10.5802/aif.3060⟩. ⟨hal-01202823v2⟩