p. 133 - 142 Preservation of tensor sum and tensor product continuous functions C. S. Kubrusly and N. Levan Received: July 26, 2010; Accepted: September 18, 2010 Abstract. This note deals with preservation of tensor sum and tensor product of Hilbert space operators. Basic operations with tensor sum are presented. The main result addresses to the problem of transferring properties from a pair of operators to their tensor sum and to their tensor product. Sufficient conditions are given to ensure that properties preserved by ordinary sum and ordinary product are preserved by tensor sum and tensor product, which are equally relevant for both finite-dimensional and infinite-dimensional spaces. Keywords: tensor product; tensor sum; Hilbert space operators AMS Subject classification: Primary: 47A80 Secondary: 47A45 PDF Compressed Postscript Version to read ISSN 0862-9544 (Printed edition) Faculty of Mathematics, Physics and Informatics Comenius University 842 48 Bratislava, Slovak Republic Telephone: + 421-2-60295111 Fax: + 421-2-65425882 e-Mail: amuc@fmph.uniba.sk Internet: www.iam.fmph.uniba.sk/amuc © 2011, ACTA MATHEMATICA UNIVERSITATIS COMENIANAE |