Generalized SAV approaches for gradient systems

We propose in this paper three generalized auxiliary scalar variable (G-SAV) approaches for developing, efficient energy stable numerical schemes gradient systems. The first two G-SAV allow a range of functions the definition SAV variable, furthermore, second approach only requires total free to be bounded from below as opposed requirement that nonlinear part below. On other hand, third is unconditionally with respect original modified energy. Ample results various systems are presented validate effectiveness and accuracy proposed approaches.