Title: Hida families of Yoshida lifts

Abstract: We construct a Hida family of Yoshida lifts for two given Hida families of modular forms. Its congruence with Hida families of stable forms on GSp4 gives rise to a lower bound on the Selmer group of the Rankin-Selberg product of the two Hida families in terms of a two-variable p-adic L-function. We study this congruence by using Rallis inner product formula, Bessel periods and Furusawa’s pullback formula.