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%Glebsky
%Lev","glebsky@cactus.iico.uaslp.mx","
\section*{On low rank perturbations of matrices} By {\sl Lev Glebsky and Luis Manuel Rivera}.  

\medskip  \noindent The talk is devoted to different aspects of the question:
 ``What can be done with a matrix by a low rank perturbation?" It is proved that one can change a geometrically simple spectrum drastically by a rank 1 perturbation, but the situation is quite different if one restricts oneself to normal matrices. Also the Jordan normal form of a perturbed matrix is discussed. It is proved that with respect to the distance $d(A,B)=\frac{\rank(A-B)}{n}$ (here $n$ is the size of the matrices) all almost unitary operators are near unitary.
%low rank, matrices","15A03","15A18","","11:04:43","Wed Feb 27 2008","189.151.26.32"
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