De Branges space

A De Branges space, named after the mathematician Louis de Branges, is a concept in functional analysis and operator theory that pertains to certain types of Hilbert spaces. Specifically, De Branges spaces are spaces of entire functions that exhibit particular growth properties and are associated with the theory of linear differential operators. In the context of entire functions, a De Branges space is typically defined by a sequence of complex numbers and involves a kernel function that generates a Hilbert space of entire functions.