PERTURBATION ANALYSIS OF THE MOORE-PENROSE INVERSE FOR A CLASS OF BOUNDED OPERATORS IN HILBERT SPACES
PERTURBATION ANALYSIS OF THE MOORE-PENROSE INVERSE FOR A CLASS OF BOUNDED OPERATORS IN HILBERT SPACES
Let <TEX>$\cal{H}$</TEX> and <TEX>$\cal{K}$</TEX> be Hilbert spaces and let T, <TEX>$\tilde{T}$</TEX> = T + <TEX>${\delta}T$</TEX> be bounded operators from <TEX>$\cal{H}$</TEX> into <TEX>$\cal{K}$</TEX>. In this article, two facts related to the perturbation bounds are studied. The first one is to find the upper bound of <TEX>$\parallel\tilde{T}^+\;-\;T^+\parallel$</TEX> which extends the results obtained …