Splitting of supervector bundles on projective superspaces
Charles Almeida, Ugo Bruzzo
TL;DR
The paper extends Horrocks-type splitting criteria to supervector bundles on the projective superspace $\mathbb{P}^{n|m}$. By leveraging the split and projected structure of $\mathbb{P}^{n|m}$ and reducing to the bosonic part, the authors show that arithmetically Cohen-Macaulay supervector bundles with vanishing intermediate cohomology split as a direct sum of even and odd line bundles when $n\ge2$ and $m\ge1$. The proof hinges on lifting a splitting from the bosonic reduction via obstruction vanishing in $H^{1}$, made possible by the fundamental exact sequence and projection-formula techniques. The result provides a concrete classification in the supergeometry setting and clarifies limitations by exhibiting non-splitting examples in low-dimensional cases, while highlighting the dependence on the split structure and the challenges for general superschemes like supergrassmannians.
Abstract
We provide a splitting criterion for supervector bundles over the projective superspaces $\mathbb{P}^{n|m}$. More precisely, we prove that a rank $p|q$ supervector bundle on $\mathbb{P}^{n|m}$ with vanishing intermediate cohomology is isomorphic to the direct sum of even and odd line bundles, provided that $n \geq 2$. For $n=1$ we provide an example of a supervector bundle that cannot be written as a sum of line bundles.
