Il est bien connu que les fréquences propres associées à un d'Alembertien amorti sont confinées dans une bande parallèle à l'axe réel. Nous rappelons l'asymptotique de Weyl pour la distribution des parties réelles des fréquences propres, nous montrons que «presque toutes» les fréquences propres appartiennent à une bande déterminée par la limite de Birkhoff du coefficient d'amortissement. Nous montrons aussi que certaines moyennes des parties imaginaires convergent vers la moyenne du coefficient d'amortissement.
@incollection{JEDP_2000____A16_0, author = {Sj\"ostrand, Johannes}, title = {Asymptotic distribution of eigenfrequencies for damped wave equations}, booktitle = {}, series = {Journ\'ees \'equations aux d\'eriv\'ees partielles}, eid = {16}, pages = {1--8}, publisher = {Universit\'e de Nantes}, year = {2000}, language = {en}, url = {http://www.numdam.org/item/JEDP_2000____A16_0/} }
Sjöstrand, Johannes. Asymptotic distribution of eigenfrequencies for damped wave equations. Journées équations aux dérivées partielles (2000), article no. 16, 8 p. http://www.numdam.org/item/JEDP_2000____A16_0/
[1] The spectrum of the damped wave operator for a bounded domain in R2. Preprint.
, ,[2] Spectral sequences for quadratic pencils and the inverse problem for the damped wave equation, J. Math. Pures et Appl., 78 (1999), 965-980. | MR | Zbl
,[3] Introduction to the theory of non-selfadjoint operators, Amer. Math. Soc., Providence, RI 1969. | Zbl
, ,[4] Equation des ondes amorties, Algebraic and geometric methods in mathematical physics (Kaciveli, 1993), 73-109, Math. Phys. Stud., 19, Kluwer Acad. Publ., Dordrecht, 1996. | Zbl
,[5] Comparison theorems for spectra of linear operators, and spectral asymptotics, Trans. Moscow Math. Soc. 1984(1), 139-187. Russian original in Trudy Moscow. Obshch. 45 (1982), 133-181. | MR | Zbl
, ,[6] Decay of solutions to nondissipative hyperbolic systems on compact manifolds, Comm. Pure. Appl. Math. 28 (1975), 501-523. | MR | Zbl
, ,[7] Asymptotic distribution of eigenfrequencies for damped wave equations, Publ. R.I.M.S., to appear. | Zbl
,[8] Density of resonances for strictly convex analytic obstacles, Can. J. Math., 48(2)(1996), 397-447. | MR | Zbl
,[9] A trace formula and review of some estimates for resonances, p.377-437 in Microlocal Analysis and spectral theory, NATO ASI Series C, vol. 490, Kluwer 1997. See also Resoances for bottles and trace formulae, Math. Nachr., to appear. | MR | Zbl
,[10] Asymptotic distribution of resonances for convex obstacles, Acta. Math., 183(2)(2000), 191. | Zbl
, ,