Hilbert–Schmidt integral operator

The Hilbert–Schmidt integral operator is a specific type of integral operator that arises in functional analysis and is connected to the theory of compact operators on Hilbert spaces. It is particularly important in the context of integral equations and various applications in mathematical physics and engineering. ### Definition Let \( K(x, y) \) be a measurable function defined on a product space \( [a, b] \times [a, b] \).