Abstract
In this paper, we establish existence and uniqueness results for single-valued as well as multi-valued (k, psi)-Hilfer boundary value problems of order in (1, 2], subject to nonlocal integromulti-point boundary conditions. In the single-valued case, we use Banach and Krasnosel'skii' fixed point theorems as well as a Leray-Schauder nonlinear alternative to derive the existence and uniqueness results. For the multi-valued problem, we prove two existence results for the convex and non-convex nature of the multi-valued map involved in a problem by applying a Leray-Schauder nonlinear alternative for multi-valued maps, and a Covitz-Nadler fixed point theorem for multi-valued contractions, respectively. Numerical examples are presented for illustration of all the obtained results.