Show that for all nonnegative integers \(k\) there is a constant \(c(k,n)<\infty \) so that for all \(u\in H^{k+2}(\mathbb {T}^n)\) we have \[ \norm {u}_{H^{k+2}(\mathbb {T}^n)}\le c\left (\norm {Lu}_{H^k(\mathbb {T}^n)}+\norm {u}_{H^0(\mathbb {T}^n)}\right ). \]
Question
Math 6410 • ODE
Fall 1997 • Question 19