G. Caterina - Department of Mathematics, Endicott College, Beverly MA, U.S.A.
V. Cafagna - Dipartimento di Matematica, Universita degli Studi di Salerno, Salerno, Italy

In this article, we explore some aspects of Fourier analysis on fuzzy sets. In particular, we give a complete characterization of the Fourier coefficients of fuzzy subsets of the unit circle. The main result hinges on a theorem by the Italian mathematician Aldo Ghizzetti. This work was part of a broader project jointly with Professor Vittorio Cafagna, who, sadly, passed away unexpectedly in ۲۰۰۷. His intellectual breadth and inspiring passion for mathematics still keeps shining today.

Fuzzy sets, fuzzy sequences, fuzzy fourier transform, Spectral Analysis