# Name of some special functions

I'd like of know if the following functions have name: Y(σ), H(σ) X(σ), Y(iω), X(iω), Y(s), X(s).

PS, I suppose that H(σ) must be the "exponential response"...

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Is there a context for these? They can be called whatever you'd like to call them without context.

AlephZero
Homework Helper
Y and H are usually types of Bessel functions, but I don't recognize X as a standard notation for anything.

Mark44
Mentor
Without some context we can't give any definitive answers. H is also used for the Heaviside step function. Y(s) is used for the Laplace transform of some function y(t). Same for X(s), but in this context, x, y, X, and Y are just function names with no special meaning.

HallsofIvy
Those are all defined in the first page you cite. "X" is the Laplace transform of whatever "input function" you have and "Y" is the Laplace transform of its "output function". H is the ratio $\frac{Y}{X}$.