{ "id": "2310.01192", "version": "v1", "published": "2023-10-02T13:29:01.000Z", "updated": "2023-10-02T13:29:01.000Z", "title": "Eigenvalues and resonances of dissipative acoustic operator for strictly convex obstacles", "authors": [ "Vesselin Petkov" ], "categories": [ "math.AP", "math-ph", "math.MP" ], "abstract": "We examine the wave equation in the exterior of a strictly convex bounded domain $K$ with dissipative boundary condition $\\partial_{\\nu} u - \\gamma(x) \\partial_t u = 0$ on the boundary $\\Gamma$ and $0 < \\gamma(x) <1, \\:\\forall x \\in \\Gamma.$ The solutions are described by a contraction semigroup $V(t) = e^{tG}, \\: t \\geq 0.$ The poles $\\lambda$ of the meromorphic incoming resolvent $(G - \\lambda)^{-1} $ with ${\\rm Re}\\: \\lambda > 0$ are called incoming resonances. We obtain sharper results for the location of the eigenvalues of $G$ and incoming resonances in $\\Lambda = \\{\\lambda \\in {\\mathbb C}:\\: |{\\rm Re}\\: \\lambda| \\leq C_2(1 + |{\\rm Im}\\: \\lambda|)^{-2},\\: |{\\rm Im}\\: \\lambda| \\geq A_2 > 1\\}$ and we prove a Weyl formula for the asymptotic of these eigenvalues and incoming resonances. For $K = \\{x \\in {\\mathbb R}^3:\\:|x| \\leq 1\\}$ and $\\gamma$ constant we show that $G$ has no eigenvalues so the Weyl formula concerns only the incoming resonances.", "revisions": [ { "version": "v1", "updated": "2023-10-02T13:29:01.000Z" } ], "analyses": { "subjects": [ "35P20", "35P25", "47A40", "58J50" ], "keywords": [ "strictly convex obstacles", "dissipative acoustic operator", "eigenvalues", "incoming resonances", "weyl formula concerns" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }