Author pages are created from data sourced from our academic publisher partnerships and public sources.

Publications Influence

Share This Author

The structure of Lie derivations on C*-algebras

- Martin Mathieu, A. Villena
- Mathematics
- 20 August 2003

We prove that every Lie derivation on a C � -algebra is in standard form, that is, it can be

The Noncommutative Singer–Wermer Conjecture and ϕ-Derivations

- M. Bresar, A. Villena
- Mathematics
- 1 December 2002

The question of when a $\phi$
-derivation on a Banach algebra has quasinilpotent values, and how this question is related to the noncommutative Singer–Wermer conjecture, is discussed.

Characterizing homomorphisms and derivations on C*-algebras

- J. Alaminos, J. Extremera, A. Villena, M. Bresar
- Mathematics
- Proceedings of the Royal Society of Edinburgh…
- 1 February 2007

The main theorem states that a bounded linear operator $h$ from a unital $C^{\ast}$-algebra $A$ into a unital Banach algebra $B$ must be a homomorphism provided that $h(\bm{1})=\bm{1}$ and the… Expand

Approximately zero-product-preserving maps

- J. Alaminos, J. Extremera, A. Villena
- Mathematics
- 20 October 2010

A continuous linear map T from a Banach algebra A into another B approximately preserves the zero products if ‖T(a)T(b)‖ ≤ α‖a‖‖b‖ (a,b ∈ A, ab = 0) for some small positive α. This paper is mainly… Expand

Approximately spectrum-preserving maps

- J. Alaminos, J. Extremera, A. Villena
- Mathematics
- 1 July 2011

Let X and Y be superreflexive complex Banach spaces and let B(X) and B(Y) be the Banach algebras of all bounded linear operators on X and Y, respectively. If a bijective linear map Φ:B(X)→B(Y) almost… Expand

Essentially defined derivations on semisimple Banach algebras

- A. Villena
- Mathematics
- 1 February 1997

We prove that every partially defined derivation on a semisimple complex Banach algebra whose domain is a (non necessarily closed) essential ideal is closable. In particular, we show that every… Expand

Characterizing Jordan maps on C*-algebras through zero products

- J. Alaminos, J. M. Brešar, J. Extremera, A. Villena
- Mathematics
- Proceedings of the Edinburgh Mathematical Society
- 5 August 2010

Abstract Let A and B be C*-algebras, let X be an essential Banach A-bimodule and let T : A → B and S : A → X be continuous linear maps with T surjective. Suppose that T(a)T(b) + T(b)T(a) = 0 and… Expand

Continuity of Lie derivations on Banach algebras

- M. I. Berenguer, A. Villena
- Mathematics
- 1 October 1998

The Lie structure induced on a Banach algebra by the bracket [a, b] — ab — ba is of lively interest for their intimate connections with the geometry of manifolds modeled on Banach spaces. Many… Expand

...

1

2

3

4

5

...