Intertwining operators over L1 (G) for G ? [PG] ? [SIN].
Invertibility preserving linear mappings into M₂(ℂ)
We study discontinuous invertibility preserving linear mappings from a Banach algebra into the algebra of n × n matrices and give an explicit representation of such a mapping when n = 2.
Invertibility-preserving maps of -algebras with real rank zero.
Isometries between groups of invertible elements in Banach algebras
We show that if T is an isometry (as metric spaces) from an open subgroup of the group of invertible elements in a unital semisimple commutative Banach algebra A onto a open subgroup of the group of invertible elements in a unital Banach algebra B, then is an isometrical group isomorphism. In particular, extends to an isometrical real algebra isomorphism from A onto B.