Electronic Journal of Differential Equations, Vol. 2024 (2024), No. 72, pp. 1-24. Title: Multiplicity results for Schrodinger type fractional p-Laplacian boundary value problems Authors: Emer Lopera (Univ. Nacional de Colombia, Manizales, Colombia) Leandro Recova (California State Polytechnic Univ, Pomona, CA, USA) Adolfo Rumbos (Pomona College, Claremont, CA, USA) Abstract: In this work, we study the existence and multiplicity of solutions to the problem $$\displaylines{ -(\Delta)_p^s u + V(x)|u|^{p-2}u = \lambda f(u),\quad x\in\Omega;\cr u=0,\quad x\in R^N\backslash\Omega, }$$ where $\Omega\subset R^N$ is an open bounded set with Lipschitz boundary $\partial\Omega$, $N\geq 2$, $V\in L^{\infty}(R^N)$, and $(-\Delta)_p^s$ denotes the fractional p-Laplacian with $s\in(0,1)$, $1
0$, and $f:R\to R$ is a continuous function. We extend the results of Lopera et al. [22] by proving the existence of a second weak solution to this problem. We apply a variant of the mountain-pass theorem due to Hofer [15] and infinite-dimensional Morse theory to obtain the existence of at least two solutions. Submitted July 15, 2024. Published November 11, 2024. Math Subject Classifications: 35J20. Key Words: Mountain pass theorem; Morse theory; critical groups; comparison principle.