Ultradistribution
In functional analysis, an ultradistribution (also called an ultra-distribution[1]) is a generalized function that extends the concept of a distributions by allowing test functions whose Fourier transforms have compact support.[2] They form an element of the dual space 𝒵′, where 𝒵 is the space of test functions whose Fourier transforms belong to 𝒟, the space of infinitely differentiable functions with compact support.[3]This mathematical analysis–related article is a stub.You can help Wikipedia by expanding it.