FOURIER EXPANSIONS AND MULTIVARIABLE BESSEL-FUNCTIONS CONCERNING RADIATION PROBLEMS

The link between generalized Bessel functions and other special functi ons is investigated using the Fourier series and the generalized Jacob i-Anger expansion. A new class of multivariable Hermite polynomials is then introduced and their relevance to physical problems discussed. A s an example of the power of the method, applied to radiation physics, we analyse the role played by multi-variable Bessel functions in the description of radiation emitted by a charge constrained to a nonlinea r oscillation.