The maximum likelihood parameter estimates for the linear model where $\Pr(Y|X\beta) \sim \mathcal{N}(0,\sigma^2)$ are:
$$\hat{\beta} = (X'X)^{-1}X'Y$$
How do you compute the statistical power of the parameter estimates? It seems that there should be a closed-form, but I've searched and haven't found a proof anywhere else online.