Suppose $ {X_t; t \in R} $ is a wss, zero mean Gaussian random process with autocorrelation function $ R_X( \tau) ; \tau \in R$ and power spectral density $S_X(\omega); \omega \in R$. If w define the random process ${Y_t;t\in R} $ by ${Y_t = ({X_t}^2)}$
What is the autocorrelation function of $Y_t$ (in terms of $\tau$)?