Cordes characterization for pseudodifferential operators with symbols valued on a noncommutative C*-algebra

TL;DR

This paper investigates the characterization of pseudodifferential operators with symbols valued in a noncommutative C*-algebra, extending known results from the commutative case to matrix algebras over A.

Contribution

It proves that surjectivity of the operator assignment for a C*-algebra A implies surjectivity for matrix algebras over A, generalizing previous results.

Findings

Surjectivity for A implies surjectivity for matrix algebras over A.

Extension of characterization results from commutative to noncommutative C*-algebras.

Analysis of pseudodifferential operators with noncommutative symbols.

Abstract

Given a separable unital C*-algebra A, let E denote the Banach-space completion of the A-valued Schwartz space on Rn with norm induced by the A-valued inner product $<f,g>=\int f(x)^*g(x) dx$. The assignment of the pseudodifferential operator B=b(x,D) with A-valued symbol b(x,\xi) to each smooth function with bounded derivatives b defines an injective mapping O, from the set of all such symbols to the set of all operators with smooth orbit under the canonical action of the Heisenberg group on the algebra of all adjointable operators on the Hilbert module E. It is known that O is surjective if A is commutative. In this paper, we show that, if O is surjective for A, then it is also surjective for the algebra of k-by-k matrices with entries in A.