Modelling with given reliability and accuracy in the space $L_p(T)$ of stochastic processes from $Sub_\varphi(Ω)$ decomposable in series with independent elements
Oleksandr Mokliachuk
TL;DR
The paper develops a general framework for modeling processes from $Sub_\varphi(\Omega)$ in $L_p(T)$ with prescribed reliability $1-\alpha$ and accuracy $\delta$, including representations as series of independent $\xi_k$ with deterministic coefficients. It derives probabilistic bounds using the Young-Fenchel transform $\varphi^*$ and Orlicz-type control $c_N$, and formulates concrete conditions to guarantee $P\{ \|X-X_N\|_{L_p(T)}>\delta\}\le \alpha$ for chosen $(\alpha,\delta)$. It also extends to processes whose expansion terms are not explicitly known by allowing approximations $\hat a_k$ and $\hat \lambda_k$, with error terms $\delta_k(t)$ and $\eta_k$, and provides Karhunen-Loève-based models when explicit eigenpairs are unavailable. As an application, the Karhunen-Loève decomposition is treated even when the integral equation cannot be solved in closed form, via approximated eigenfunctions/eigenvalues and Mercer's representation.
Abstract
Models that approximate stochastic processes from $Sub_\varphi(Ω)$ with given reliability and accuracy in $L_p(T)$ for some given $\varphi(t)$ are considered. We also study construction of models of processes which can be decomposed into series with approximate elements. Karhunen-Lo{è}ve model is considered as an example of the application of the proposed construction.
