IAM   02674
INSTITUTO ARGENTINO DE MATEMATICA ALBERTO CALDERON
Unidad Ejecutora - UE
artículos
Título:
Schur-Horn theorems in II_\infty-factors.
Autor/es:
ARGERAMI, MARTIN; MASSEY, PEDRO
Revista:
PACIFIC JOURNAL OF MATHEMATICS
Editorial:
PACIFIC JOURNAL MATHEMATICS
Referencias:
Lugar: Los Angeles, California; Año: 2013 vol. 261 p. 283 - 283
ISSN:
0030-8730
Resumen:
We describe majorization between selfadjoint operators in a semi-finite II_\infty factor (M;\tau) in terms of simple spectral relations. For a difuse abelian von Neumann subalgebra A  of M that admits a (necessarily unique) trace-preserving conditional expectation, denoted by E_A, we characterize the closure in the measure topology of the image through E_A of the unitary orbit of a selfadjoint operator in M in terms of majorization (i.e., a Schur-Horn theorem). We also obtain similar results for the contractive orbit of positive operators in M and for the unitary and contractive orbits of \tau-integrable selfadjoint operators in M.