Four-variable $p$-adic triple product $L$-functions and the trivial zero conjecture

We construct the four-variable primitive $p$-adic $L$-functions associated with the triple product of Hida families and prove the explicit interpolation formulae at all critical values in the balanced range. Our construction is to carry out the $p$-adic interpolation of Garrett's integral representation of triple product $L$-functions via the $p$-adic Rankin-Selberg convolution method. As an application, we obtain the cyclotomic $p$-adic $L$-function for the motive associated with the triple product of elliptic curves and prove the trivial zero conjecture for this motive.