Fast Fourier Transform on Symmetric Group Maso Koyama Abstract: Discrete Fourier Transform (DFT) is a popular tool used in many fields of physical science to convert a signal in the time domain to a signal in the frequency domain. Fast Fourier Transform is an efficient implementation of DFT. In this talk, we will interpret DFT as change of basis in group algebra $\mathbb{C}G$. In particular, we will consider the case in which $G =S_n.$ I would introduce Specht module, and describe a specific method of FFT on $\mathbb{C}S_n.$