One-loop on-shell and off-shell decay $H^{\ast }\to VV$ at future $e^{-}{e}^{-}$ collider

One-loop on-shell and off-shell decays $H\to VV$ with $VV=\gamma \gamma ,Z\gamma ,ZZ$ are presented in this paper. The effects of one-loop on-shell and off-shell Higgs decays in Higgs productions at $e^{-}{e}^{-}$ collisions are also then examined. We find that the impacts of one-loop Higgs decays are significant and they are must be taken into account at $e^{-}{e}^{-}$ collision.