On transversally elliptic operators and the quantization of manifolds with $f$-structure

Abstract

An $f$-structure on a manifold $M$ is an endomorphism field $ϕ\inΓ(M,\End(TM))$ such that ${\varphi }^3+\varphi =0$. Any $f$-structure $\varphi$ determines an almost CR structure $E_{1,0}\subset T_\C M$ given by the $+i$-eigenbundle of $\varphi$. Using a compatible metric $g$ and connection $\nabla$ on $M$, we construct an odd first-order differential operator $D$, acting on sections of $\S =\Lambda E_{0,1}^{\ast }$, whose principal symbol is of the type considered in arXiv:0810.0338. In the special case of a CR-integrable almost $\S$-structure, we show that when $\nabla$ is the generalized Tanaka-Webster connection of Lotta and Pastore, the operator $D$ is given by $D = \sqrt{2}(\dbbar+\dbbar^*)$, where $\dbbar$ is the tangential Cauchy-Riemann operator. We then describe two "quantizations" of manifolds with $f$-structure that reduce to familiar methods in symplectic geometry in the case that $\varphi$ is a compatible almost complex structure, and to the contact quantization defined in \cite{F4} when $\varphi$ comes from a contact metric structure. The first is an index-theoretic approach involving the operator $D$; for certain group actions $D$ will be transversally elliptic, and using the results in arXiv:0810.0338, we can give a Riemann-Roch type formula for its index. The second approach uses an analogue of the polarized sections of a prequantum line bundle, with a CR structure playing the role of a complex polarization.

31 pages

References in corpus (2)

• On the geometric quantization of contact manifolds
• On the geometry of almost $\mathcal{S}$-manifolds

Cited by in corpus (1)

• On the geometry of almost $\mathcal{S}$-manifolds