Conservation of the noetherianity by perfect transcendental field extensions

Let k be a perfect field of characteristic p>0, k(t)per the perfect closure of k(t) and A a k-algebra. We characterize whether the ring A⊗kk(t)per is noetherian when A is the ring of formal power series in n indeterminates over k.Dirección General de Enseñanza Superior e Investigación Científic