Symbols in Noncommutative Geometry

TL;DR

This paper extends the classical Lie bracket to noncommutative geometry by developing a theory of symbols and jet modules, providing conditions for differential operators and their algebraic structures in a noncommutative setting.

Contribution

It introduces a generalized Lie bracket in noncommutative geometry and establishes a comprehensive theory of symbols and jet modules for differential operators.

Findings

Generalization of Lie brackets to noncommutative setting

Necessary and sufficient conditions for jet modules as differential operator representations

Development of an extensive theory of symbols in noncommutative geometry

Abstract

In this paper we prove that the classical Lie bracket of vector fields can be generalized to the noncommutative setting by antisymmetrizing (in a suitable noncommutative sense) their compositions. This construction turns out to depend on the representability of linear differential operators, as it relies on the interpretation of vector fields as differential operators. In particular we provide necessary and sufficient conditions for (noncommutative) jet modules to be representing objects for differential operators. Furthermore, the primary ingredient for guaranteeing the closure of a bracket operation is a treatment of symbols, which classically represent, in an intrinsic way, the highest-order term of a differential operator. Thus, we provide an extensive theory of symbols herein.