Chapter 14 Time Series 2: top line of Pg 24 would someone mind elaborating on how the log-likelihood function is calculated (especially where the -1/2 multiplier comes from and why it is squared) as I couldnt follow how this is calculated from the linear regression model given in the question. Many thanks in advance
I think you mean p25 (2020 version of notes). Anyway, Yi ~N(a+bxi, sigma^2) and L = product from i=1 to n of f(yi). Formula for f is given on p11 of Tables. Replace mu by a + bxi in this formula, and replace x by yi. Once you have L, take logs.