18 citations · 18 across the 5 of their papers we have counts for
7 papers · 1 filter
A class of preservers on Hilbert space effects including ortho-order automorphisms and sequential automorphisms
Lajos Molnar
In this paper we study a new class of transformations on the set of all Hilbert space effects. This consists of the bijective maps which preserve the order and zero product in both…
Orthogonality preserving transformations on indefinite inner product spaces: Generalization of Uhlhorn's version of Wigner's theorem
Lajos Molnar
We present an analogue of Uhlhorn's version of Wigner's theorem on symmetry transformations for the case of indefinite inner product spaces. This significantly generalizes a result…
Reflexivity of the isometry group of some classical spaces
Felix Cabello Sanchez, Lajos Molnar
We investigate the reflexivity of the isometry group and the automorphism group of some important metric linear spaces and algebras. The paper consists of the following sections: 1…
A Wigner-type theorem in Banach spaces
Lajos Molnar
We obtain an anlogue of Wigner's classical theorem on symmetries for Banach spaces. The proof is based on a result from the theory of linear preservers. Moreover, we present two ot…
Some characterizations of the automorphisms of and
Lajos Molnar
We present some nonlinear characterizations of the automorphisms of the operator algebra and the function algebra by means of their spectrum preserving properties.
On certain automorphisms of sets of partial isometries
Lajos Molnar
Under the mild condition of continuity at a single point we describe all the bijections of the set of all partial isometries on a Hilbert space which preserve the order and the ort…