z-logo
Premium
Bushell's equations and polar decompositions
Author(s) -
Lim Yongdo
Publication year - 2009
Publication title -
mathematische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 50
eISSN - 1522-2616
pISSN - 0025-584X
DOI - 10.1002/mana.200610820
Subject(s) - mathematics , positive definite matrix , polar decomposition , invertible matrix , pure mathematics , homeomorphism (graph theory) , hilbert space , banach space , operator (biology) , unitary state , sesquilinear form , mathematical analysis , combinatorics , polar , hermitian matrix , eigenvalues and eigenvectors , biochemistry , physics , chemistry , repressor , quantum mechanics , astronomy , transcription factor , gene , political science , law
We show that for any real number t with t ≠ ±1, every invertible operator M on a Hilbert space admits a new polar decomposition M = PUP –t where P is positive definite and U is unitary, and that the corresponding polar map is homeomorphism. The positive definite factor P of M appears as the negative square root of the unique positive definite solution of the nonlinear operator equation X t = M * XM . This extends the classical matrix and operator polar decomposition when t = 0. For t = ± 1, it is shown that the positive definite solution sets of X ±1 = M * XM form geodesic submanifolds of the Banach–Finsler manifold of positive definite operators and coincide with fixed point sets of certain non‐expansive mappings, respectively (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here
Accelerating Research

Address

John Eccles House
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom