Km. Abadir et R. Larsson, The joint moment generating function of quadratic forms in multivariate autoregressive series - The case with deterministic components, ECONOMET TH, 17(1), 2001, pp. 222-246
Let {X-t} follow a discrete Gaussian vector autoregression with determinist
ic components. We derive the exact finite-sample joint moment generating fu
nction (MCF) of the quadratic forms that form the basis for the sufficient
statistic. The formula is then specialized to the limiting MGF of functiona
ls involving multivariate and univariate Ornstein-Uhlenbeck processes, drif
ts, and time trends. Such processes arise asymptotically from more general
non-Gaussian processes and also from the Gaussian {X-t} and have also been
used in areas other than time series, such as the "goodness of fit" literat
ure.