Semiclassical Geometry of Quantum Line Bundles and Morita Equivalence of Star Products

Abstract

In this paper we show how deformation quantization of line bundles over a Poisson manifold $M$ produces a canonical action $\Phi$ of the Picard group $\Pic(M)\cong H^2(M,\mathbb Z)$ on the moduli space of equivalence classes of differential star products on $M$, $\Def(M)$. The orbits of $\Phi$ characterize Morita equivalent star products on $M$. We describe the semiclassical limit of $\Phi$ in terms of the characteristic classes of star products by studying the semiclassical geometry of deformed line bundles.