Recent Publications (Last Update 2004)

Specral isometries of operator algebras,
(with M. Mathieu),
Archiv der Mathematik, 2004 pdf

Linear maps on matrix algebra that preserve the numerical range,
numerical radius or the states
(with C. K. Li),
Cnd. J. Math. 56, (2004), 134  167.
pdf

Isometries of block triangular matrix algebras with respect to KyFan norms,
(with C. K. Li and P. Semrl),
Archiv der Mathematik, to appear.
81, (2003), 175  181.
pdf

The semigroup generated by a similarity orbit or a unitary orbit of an
operator, (with C.K. Fong)
Proc. Amer. Math. Soc., 131 (2003), 3203  3210.
pdf
 Conjugationinvariant subspaces and Lie ideals in
nonselfadjoint opeartor algebras, (with L. W. Marcoux)
J. London Math. Soc. (2)
65(2002), 493512.
pdf

Three linear preserver problems, Mathematics and the 21st century
211221, World Sci. Publ. 2001.
pdf

Semigroups generated by similarity orbits (with
L. Grunenfelder, M. Omladic and H. Radjavi)
Semigroup Forum, 62(2001), 460472.
pdf

Inequalities for products of spectral radii (with M. Omladic,
H. Radjavi and P. Rosenthal)
Proc. Amer. Math. Soc., 129(2001), 22392243.

Additive rankone preserving mappings on triangular matrix algebras
(with J. Bell)
Lin. Alg. Appl. 312 (2000), 1333.
pdf
A copy of this paper is available from Lin. Alg. Appl.
Click here Then go to the June 2000 issue.
 Lie isomorphisms of nest algebras, (with L. W. Marcoux),
J. Funct. Anal., 164 (1999), 163180.
pdf

Maps on matrices that preserve the spectral radius distance,
(with R. Bhatia and P. Semrl),
Studia Math. 134 (1999), 99110.

Commutativity preserving linear maps and Lie automorphisms of triangular
matrix algebras (with L. W. Marcoux),
Lin. Alg. Appl. 288 (1999), 89104
pdf
A copy of this paper is available from Lin. Alg. Appl.
Click here Then go to the February 1999 issue.

Lie ideals in triangular operator algebras
(with T. D. Hudson and L. W. Marcoux),
Trans. Amer. Math. Soc. 350 (1998), 33213339.
pdf
A copy of this paper is available from the American Mathematical Society.&nb
sp;
Click here.

Invertivility preserving linear maps on L(X),
Trans. Amer. Math. Soc. 350 (1998), 33213339.
A copy of this paper
is available from the American Mathematical Society. Click
here.

Simultaneous triangularizability, near commutativity and Rota's theorem
(with A. A. Jafarian, H. Radjavi and P. Rosenthal)
Trans. Amer. Math. Soc.
347 (1995), no. 6, 21912199.

Spectral properties of the the operator equation AX+XB=C (with
W. Arendt and F. Räbiger)
Quart. J. Math. Oxford Ser. (2)
45 (1994), no. 6, 133149.