On Deligne's conjecture for symmetric fourth L-functions of Hilbert modular forms

Abstract

We prove an automorphic analogue of Deligne's conjecture for symmetric fourth L-functions of Hilbert modular forms. We extend the result of Morimoto [41] based on generalization and refinement of the results of Grobner and Lin [18] to cohomological irreducible essentially conjugate self-dual cuspidal automorphic representations of GL2 and GL3 over CM-fields.