## Another look at Cwikel’s inequality.(English)Zbl 0922.35106

Buslaev, V. (ed.) et al., Differential operators and spectral theory. M. Sh. Birman’s 70th anniversary collection. Providence, RI: American Mathematical Society. Transl., Ser. 2, Am. Math. Soc. 189(41), 247-254 (1999).
Summary: We point out the basic bound on the singular values of integral operators of the type $$a(x)b(D)$$, from which Cwikel’s inequality and its generalizations can easily be derived.
For the entire collection see [Zbl 0911.00011].

### MSC:

 35P15 Estimates of eigenvalues in context of PDEs 45C05 Eigenvalue problems for integral equations

### Keywords:

singular values of integral operators