Kuiper's theorem
It states that the space GL ( "H" ) of invertible bounded endomorphisms of "H" is such that all maps from any finite complex "Y" to GL ( "H" ) are homotopic to a constant , for the norm topology on operators . 
<triplet> finite complex <subj> space <obj> subclass of <triplet> norm topology <subj> endomorphisms <obj> subclass of