Published February 15, 1994 | Version public
Journal Article

The Index of a Pair of Projections

  • 1. ROR icon Technion – Israel Institute of Technology
  • 2. ROR icon Technical University of Berlin

Abstract

We discuss pairs of self-adjoint projections with P − Q ∈ J_(2n + 1), the trace ideal, and prove that for m ≥ n, tr(P − Q)^(2m + 1) = tr(P − Q)^(2n + 1) = dim(Ker Q ∩ Ran P) − dim(Ker P ∩ Ran Q) is an integer. We also prove that there exists a unitary V interchanging P and Q if and only if this integer is 0.

Additional Information

© 1994 Academic Press. Received March 1, 1993. Communicated by L. Gross. Research partially supported by US NSF Grant DMS-9101715. We thank M. Ben-Artzi for the hospitality of Hebrew University where some of this work was done and I. Kaplansky for a useful question. The research is partially supported by GIF.

Additional details

Identifiers

Eprint ID
81208
Resolver ID
CaltechAUTHORS:20170906-144540972

Funding

NSF
DMS-9101715
German-Israeli Foundation for Research and Development

Dates

Created
2017-09-06
Created from EPrint's datestamp field
Updated
2021-11-15
Created from EPrint's last_modified field

Caltech Custom Metadata