Inverting weak random operators

Abstract

Abstract We analyze two weak random operators, initially motivated from processes in random environment. At first glance, these operators are ill-defined, but using bilinear forms, one can deal with them in a rigorous way. This point of view can be found, for instance, in [A. V. Skorohod, Random Linear Operators, Math. Appl. (Sov. Ser.), D. Reidel Publishing, Dordrecht, 1984], and it remarkably helps to carry out specific calculations. In this paper, we find explicitly the inverse of such weak operators by providing the closed forms of the so-called Green kernel. We show how this approach helps to analyze the spectra of the operators. In addition, we provide the existence of strong operators associated to our bilinear forms. Important tools that we use are the Sturm–Liouville theory and the stochastic calculus.