Abstract:
In the article we define a Banach algebra of periodic at infinity functions. For this class of functions we introduce the notions of a Fourier series, its absolutely convergence and invertibility. We obtain an analogue of Wiener theorem on absolutely convergent Fourier series for periodic at infinity functions whose Fourier coefficients are summable with a weight.
Keywords:Banach space, slowly varying at infinity functions, periodic at infinity functions, Wiener theorem, absolutely convergent Fourier series, invertibility.