Agmon's inequality

In mathematical analysis, Agmon's inequalities, named after Shmuel Agmon,[1] consist of a few closely related inequalities between the Lebesgue space L^\infty and the Sobolev spaces H^s. It is useful in the study of partial differential equations.

The result is stated in \mathbb{R}^3 only. Let u be a vector-valued function, u\in (H^2(\Omega)\cap H^1_0(\Omega))^3 where \Omega\subset\mathbb{R}^3. Then Agmon's inequalities state that there exists a constant C such that

\displaystyle \|u\|_{L^\infty(\Omega)}\leq C \|u\|_{L^2(\Omega)}^{1/4} \|u\|_{H^2(\Omega)}^{3/4}

and

\displaystyle \|u\|_{L^\infty(\Omega)}\leq C \|u\|_{H^1(\Omega)}^{1/2} \|u\|_{H^2(\Omega)}^{1/2}.

References

Notes

  1. ^ Lemma 13.2, in: Agmon, Shmuel, Lectures on Elliptic Boundary Value Problems, AMS Chelsea Publishing, Providence, RI, 2010. ISBN 978-0-8218-4910-1.