Rigged Hilbert spaces, often known as Gelfand triplets, extend the standard Hilbert space framework to incorporate both square-integrable states and more singular objects such as generalised ...

Hilbert space theory and operator algebras provide a robust framework for analysing linear operators and their spectral properties, which are pivotal in both pure and applied mathematics. Hilbert ...

Perhaps the most beautiful aspect of mathematics is that it applies to literally everything, even things that do not exist in this Universe. In addition to this there are a number of alternative ways ...