Spectral theory and harmonic analysis of the Laplacian and other elliptic operators, including Fourier inversion.

1. Fourier integral operators and harmonic analysis on compact manifolds

2. Lp bounds on functions of generalized Laplacians on a compact manifold with boundary

3. Hardy spaces and bmo on manifolds with bounded geometry

4. Double Fourier series of functions with simple singularities – a graphical case study. (OK, this is not a pdf file.)

5. Flat 2D tori with sparse spectra

6. Variations on Gel’fand’s inverse spectral problem

7. Serendipitous Fourier inversion

8. The Schrodinger equation and Gauss sums

9. Multivariate Gauss sums

10. Simple potential wells in R3 as a model for the deuteron (This note discusses a discrepancy between a calculation of mine and some results reported in some nuclear physics texts)

11. Multiple eigenvalues of operators with noncommutative symmetry groups

12. Variations on quantum ergodic theorems

13. Critical Besov space embedding into bmo

14. Selfadjoint perturbation theory in the discrete case

15. Joint spectra of Riemannian manifolds with rotational symmetry

16. Spectral asymptotics of a product of 2-spheres

17. Elliptic operators on S^2 whose Weyl asymptotics have small remainders

18. Product manifolds with small Weyl remainders

19. Potentials in the Kato class of measures, and other very singular potentials

20. Remarks on the hydrogen atom Schrodinger operator

21. Functional calculus and Littlewood-Paley theory for Schrodinger operators

22. Manifolds whose Weyl asymptotics have small but not tiny remainders

Here’s a paper developing semiclassical analysis in the setting of spectral theory.

1. Semiclassical spectra of gauge fields (with A. Uribe, J. Funct. Anal. 110 (1992))

We also treat spectral theory for some sublaplacians.

1. Spectral asymptotics for a spherical sublaplacian

2. Eigenfunction concentration results