[Math] What does “kernel” mean in integral kernel

fa.functional-analysisintegral-kernel

In functional analysis, there is the term "integral kernel". Examples are Possion kernel, Dirichlet kernel etc.

In algebra, the term kernel of a homomorphism refers to the inverse image of the zero element.

Are these two terms related? If not, where did the word "kernel" in the term "integral kernel" come from?

Best Answer

I think it simply denotes the inner part.

According to dictionary, kernel is "the important, central part of anything". (This is the third meaning in Chambers Concise Dictionary). From O.E. cyrnel=corn,grain + dimin. suffix -el).

I also know the kernel of an operating system.