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Publications Influence

Local derivations and local automorphisms of B(X)

- D. Larson, A. Sourour
- Mathematics
- 1988

189 15

Isometries of norm ideals of compact operators

- A. Sourour
- Mathematics
- 1 August 1981

Abstract Let J be a symmetric norm ideal of compact operators on Hilbert space H , and assume that the finite rank operators are dense in J and that J is not the ideal of Hilbert-Schmidt operators. A… Expand

48 8

A factorization theorem for matrices

- A. Sourour
- Mathematics
- 1 April 1986

It is shown that a nonscalar invertible square matrix can be written as a product of two square matrices with prescribed eigenvalues subject only to the obvious determinant condition. As corollaries,… Expand

67 5

INVERTIBILITY PRESERVING LINEAR MAPS ON L(X)

- A. Sourour
- Mathematics
- 1996

For Banach spaces X and Y , we show that every unital bijective invertibility preserving linear map between L(X) and L(Y ) is a Jordan isomorphism. The same conclusion holds for maps between CI +… Expand

118 4- PDF

Lie and Jordan ideals of operators on Hilbert space

- C. Fong, C. Miers, A. Sourour
- Mathematics
- 1 April 1982

A linear manifold 2 in ©(§) is a Lie ideal in 33(§) if and only if there is an associative ideal 5 such that (S. ^(C)) C 2 c S + CI. Also S is a Lie ideal if and only if it contains the unitary orbit… Expand

42 3- PDF

Additive rank-one preserving mappings on triangular matrix algebras

- J. Bell, A. Sourour
- Mathematics
- 15 June 2000

Abstract We classify surjective additive maps on the space of block upper triangular matrices that preserve matrices of rank one as well as linear maps preserving matrices of rank one on fairly… Expand

29 3- PDF

Sums and products of quasi-nilpotent operators

- C. Fong, A. Sourour
- Mathematics
- 1984

It is proved that a bounded operator on Hilbert space is the sum of two quasi-nilpotent operators if and only if it is not a non-zero scalar plus a compact operator. Necessary conditions and… Expand

16 3

LIE ISOMORPHISMS OF NEST ALGEBRAS

- L. Marcoux, A. Sourour
- Mathematics
- 10 May 1999

Abstract In this paper we characterize linear maps ϕ between two nest algebras T ( N ) and T ( M ) which satisfy the property that ϕ ( AB − BA )= ϕ ( A ) ϕ ( B )− ϕ ( B ) ϕ ( A ) for all A , B ∈ T… Expand

37 3- PDF

Spectrum-preserving linear maps

- A. Jafarian, A. Sourour
- Mathematics
- 1 April 1986

Abstract Let X and Y be Banach spaces. We show that a spectrum preserving surjective linear map φ from B ( X ) to B ( Y ) is either of the form φ ( T ) = ATA −1 for an isomorphism A of X onto Y or… Expand

166 3- PDF

SPECTRAL PROPERTIES OF THE OPERATOR EQUATION AX + XB = Y

- W. Arendt, F. Räbiger, A. Sourour
- Mathematics
- 1 June 1994

(under the assumption o(A) =£ C or o(B) =£ C), so that 0 £ o(A) + o(B) is a necessary condition for existence and uniqueness of (0.1). The proof of (0.3) we give in Section 2 seems to be new even for… Expand

59 2- PDF