Holomorphic Jet Modules and Holomorphic Connections for Noncommutative Complex Curves

Abstract

We extend Atiyah's holomorphic jet bundle formalism to holomorphic vector bundles over noncommutative algebras endowed with a bigraded differential calculus truncated at bidegree $(1,1)$; such structures are referred to as noncommutative complex curves. For a holomorphic vector bundle $(E,{\overline{\nabla }}_E)$ over such an algebra $\mathcal{A}$, we construct a canonical holomorphic structure ${\overline{\nabla }}_J$ on the first jet module $J_E^1$, making the jet sequence \[ 0\longrightarrow Ω^{1,0}(\mathcal{A})\otimes_{\mathcal A}E \longrightarrow J_E^1 \longrightarrow E \longrightarrow 0 \] exact in the holomorphic category. The assignment $(E,{\overline{\nabla }}_E)⇝(J_E^1,{\overline{\nabla }}_J)$ defines an endofunctor on the category of holomorphic vector bundles over $\mathcal{A}$. We define the notion of holomorphic connection in this setting and prove that a holomorphic vector bundle admits a holomorphic connection if and only if the above jet sequence splits in the holomorphic category, or equivalently, if and only if its Atiyah class vanishes. This yields a noncommutative analogue of Atiyah's classical correspondence for Riemann surfaces. Finally, we specialize to the quantum projective line ${\mathbb{CP}}_q^1$ and determine when ${\overline{\nabla }}_J$ defines a bimodule connection, assuming that ${\overline{\nabla }}_E$ does so.

A few typos corrected, To appear in J. Noncommut. Geom