The detection of GW170817 and its electromagnetic counterpart has revealed the speed of gravitational waves coincides with the speed of light , c _ { T } = 1 .
Inspired by the possibility that the physics implied by GW170817 might be related with that for the primordial universe , we construct the spatially flat stable ( throughout the whole evolution ) nonsingular bounce models in the beyond Horndeski theory with c _ { T } = 1 and in the degenerate higher-order scalar-tensor ( DHOST ) theory with c _ { T } = 1 , respectively .
Though it constricts the space of viable models , the constraint of c _ { T } = 1 makes the procedure of building models simpler .