Strictly singular operator
= Strictly singular operator
{wiki=Strictly_singular_operator}
In functional analysis, a strictly singular operator is a type of linear operator that exhibits particularly strong properties of compactness. Specifically, an operator \\( T: X \\to Y \\) between two Banach spaces \\( X \\) and \\( Y \\) is defined as strictly singular if it is not an isomorphism on any infinite-dimensional subspace of \\( X \\).