We give the governing equations for multiple scalar fields in a flat Friedmann-Robertson-Walker (FRW) background spacetime on all scales, allowing for metric and field perturbations up to second order. We then derive the Klein-Gordon equation at second order in closed form in terms of gaugeinvariant perturbations of the fields in the uniform curvature gauge. We also give a simplified form of th...

A noise-compensated long correlation matching (NCLCM) method is proposed for autoregressi~e ~AR) spectral estimation of the noisy AR signals. This method first computes the AR parameters from the high-order "(ule-Walker equations. Next, it employs these AR parameters and uses the low-order Yule-Walker equations to compensate the zeroth autocorrelation coefficient for the additive white noise. F...

Dandy-Walker malformation is a rare congenital malformation and involves the cerebellum and fourth ventricle. The condition is characterized by agenesis or hypoplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle, and enlargement of the posterior fossa. A large number of concomitant problems may be present, but the syndrome exists whenever these three features are found. A...