K-space (functional analysis)

In mathematics, more specifically in functional analysis, a K-space is an F-space such that every extension of F-spaces (or twisted sum) of the form

is equivalent to the trivial one where is the real line.

Examples

The spaces for are K-spaces, as are all finite dimensional Banach spaces.

N. J. Kalton and N. P. Roberts proved that the Banach space is not a K-space.

See also