Invariance of Grothendieck-Witt groups under subintegral extensions and cancellation of quadratic spaces

Motivated by the work of Ischebeck on the behaviour of algebraic $K$-theoretic functors under subintegral extensions, we investigate the analogous question in Hermitian $K$-theory. We prove that Grothendieck-Witt groups in degree zero are invariant under subintegral extensions. We also investigate t