Geodesic Lévy flights and expected stopping time for random searches

We give an analytic description for the infinitesimal generator constructed in Applebaum and Estrade (Ann Probab 28(1):166-184, 2000) for Lévy flights on a broad class of closed Riemannian manifolds including all negatively-curved manifolds, the flat torus and the sphere. Various properties of the associated semigroup and the asymptotics of the expected stopping time for Lévy flight based random searches for small targets, also known as the “narrow capture problem", are then obtained using our newfound understanding of the infinitesimal generator. Our study also relates to the Lévy flight foraging hypothesis in the field of biology as we compute the expected time for finding a small target by using the Lévy flight random search. Compared to the random search time for Brownian motion on surfaces done in Nursultanov et al. (arXiv:2209.12425), our result suggests that Lévy flight may not always be the optimal strategy, consistent with the conclusion obtained in Palyulin et al. (Proc Natl Acad Sci 111(8):2931-2936, 2014) for the one dimensional case.