Solitons and soliton molecules in two nonlocal Alice–Bob Sawada–Kotera systems

Two nonlocal Alice–Bob Sawada–Kotera (ABSK) systems, accompanied by the parity and time reversal invariance are studied. The Lax pairs of two systems are uniformly written out in matrix form. The periodic waves, multiple solitons, and soliton molecules of the ABSK systems are obtained via the bilinear method and the velocity resonant mechanism. Though the interactions among solitons are elastic, the interactions between soliton and soliton molecules are not elastic. In particular, the shapes of the soliton molecules are changed explicitly after interactions.