Published online by Cambridge University Press: 09 February 2023
This paper addresses the asymptotic analysis of sojourn functionals of spatiotemporal Gaussian random fields with long-range dependence (LRD) in time, also known as long memory. Specifically, reduction theorems are derived for local functionals of nonlinear transformation of such fields, with Hermite rank  $m\geq 1,$ under general covariance structures. These results are proven to hold, in particular, for a family of nonseparable covariance structures belonging to the Gneiting class. For
$m\geq 1,$ under general covariance structures. These results are proven to hold, in particular, for a family of nonseparable covariance structures belonging to the Gneiting class. For  $m=2,$ under separability of the spatiotemporal covariance function in space and time, the properly normalized Minkowski functional, involving the modulus of a Gaussian random field, converges in distribution to the Rosenblatt-type limiting distribution for a suitable range of values of the long-memory parameter.
$m=2,$ under separability of the spatiotemporal covariance function in space and time, the properly normalized Minkowski functional, involving the modulus of a Gaussian random field, converges in distribution to the Rosenblatt-type limiting distribution for a suitable range of values of the long-memory parameter.
 $\mathbb{R}^{n}.$ J. Contemp. Math. Anal. 55, 329–334.Google Scholar
$\mathbb{R}^{n}.$ J. Contemp. Math. Anal. 55, 329–334.Google Scholar $\mathbb{S}^{2}\times \mathbb{R}.$ Ann. Appl. Prob. 31, 2311–2349.Google Scholar
$\mathbb{S}^{2}\times \mathbb{R}.$ Ann. Appl. Prob. 31, 2311–2349.Google Scholar