Riesz projector

The Riesz projector is a mathematical concept that arises in functional analysis, particularly in the context of spectral theory of linear operators. It is named after the Hungarian mathematician Frigyes Riesz. ### Definition Given a bounded linear operator \( T \) on a Banach space, the Riesz projector associated with \( T \) is a projection operator that projects onto the eigenspace corresponding to a specific point in the spectrum of \( T \).