We prove the existence of limiting laws for symmetric stable-like processes penalized by generalized Feynman-Kac functionals and characterize them by the gauge functions and the ground states of Schrodinger type operators.
Introduction.In this paper we study limit theorems for symmetric stable-like processes on R d penalized by normalized Feynman-Kac functionals as the weight processes.Penalizing measures by appropriate weight processes can be understood as a change-ofmeasure phenomenon and such modifications have been studied by many authors ([16, 18, 21, 25]). In penalizations, the weights play a role analogous to a Girsanov transform in which its martingale property allows to define a new probability measure, do not allow immediately to create a new weighted probability measure that may emerge in the limit of weight processes. When such a limit exists, it is called the penalized probability measure associated with the weights.In [18], Roynette, Vallois and Yor have studied limit theorems for Wiener processes penalized by various weight processes. In [25], the authors studied limit theorems for the onedimensional symmetric stable process penalized by Feynman-Kac transforms with negative (killing) additive functionals, and they called their limit theorems the Feynman-Kac penalizations. It turns out that their methods are not available in multi-dimensional cases. In [21], Takeda extended their results to Feynman-Kac transforms with positive (creation) continuous additive functionals corresponding to positive smooth measures for multi-dimensional symmetric stable processes on R d by classifying associated Schrödinger operators of Feynman-Kac semigroups into the subcritical, critical and supercritical cases, and by characterizing the penalized measures in each cases. Recently, this result was extended to non-local Feynman-Kac transforms by Matsuura [16].The purpose of this paper is to extend the previous results for penalization problems to the so-called generalized Feynman-Kac transforms. More precisely, let X = (Ω, F ∞ , F t ,X t ,P x ) be the symmetric α-stable-like process on R d with 0 < α < 2 and (E, F ) the associated