{ "id": "2005.10323", "version": "v1", "published": "2020-05-20T19:17:43.000Z", "updated": "2020-05-20T19:17:43.000Z", "title": "Weyl formulae for Schrödinger operators with critically singular potentials", "authors": [ "Xiaoqi Huang", "Christopher D. Sogge" ], "categories": [ "math.AP", "math.CA", "math.DG", "math.SP" ], "abstract": "We obtain generalizations of classical versions of the Weyl formula involving Schr\\\"odinger operators $H_V=-\\Delta_g+V(x)$ on compact boundaryless Riemannian manifolds with critically singular potentials $V$. In particular, we extend the classical results of Avakumovi\\'{c} , Levitan and H\\\"ormander by obtaining $O(\\lambda^{n-1})$ bounds for the error term in the Weyl formula in the universal case when we merely assume that $V$ belongs to the Kato class, ${\\mathcal K}(M)$, which is the minimal assumption to ensure that $H_V$ is essentially self-adjoint and bounded from below or has favorable heat kernel bounds. In this case, we can also obtain extensions of the Duistermaat-Guillemin theorem yielding $o(\\lambda^{n-1})$ bounds for the error term under generic conditions on the geodesic flow, and we can also extend B\\'erard's theorem yielding $O(\\lambda^{n-1}/\\log \\lambda)$ error bounds under the assumption that the principal curvatures are non-positive everywhere. We can obtain further improvements for tori, which are essentially optimal, if we strengthen the assumption on the potential to $V\\in L^p(M)\\cap {\\mathcal K}(M)$ for appropriate exponents $p=p_n$.", "revisions": [ { "version": "v1", "updated": "2020-05-20T19:17:43.000Z" } ], "analyses": { "subjects": [ "58J50", "35P15" ], "keywords": [ "critically singular potentials", "weyl formula", "schrödinger operators", "error term", "compact boundaryless riemannian manifolds" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }