“…x ∈ Ω and all t ∈ R for some s ∈ (p, q) and c > 0. Recently, Liu and Dai [1] investigated the sign-changing ground state solution of (P) under (h 1 ), (h 2 ), (h 3 ), and (h 4 ) the function t → f (x,t) |t| q-1 is strictly increasing on (-∞, 0) ∪ (0, +∞). Additionally, Liu and Dai [9] also obtained the existence of at least three ground state solutions of (P) by using the strong maximum principle for the homogeneous doublephase problem.…”