Trapped modes in acoustic waveguides
Trapped modes in acoustic waveguides
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DOI：
10.1093/qjmam/51.3.477
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发表时间：
1998-08-01
影响因子：
0.9
通讯作者：
Parnovski, L
中科院分区：
文献类型：
--
作者：
Davies, EB;Parnovski, L
考虑了具有诺依曼边界条件的圆柱上受紧障碍物扰动的拉普拉斯算子的特征值问题，并寻找了该问题的特征值。对于具有对称障碍物的二维圆柱体，给出了特征值存在和不存在的充分条件。我们还证明了在平行于圆柱体轴线的薄障碍物的情况下，总是存在一个特征值。
We consider the eigenvalue problem for the Laplacian on a cylinder perturbed by a compact obstacle (with Neumann boundary conditions) and look for eigenvalues of such a problem. In the case of a two-dimensional cylinder with symmetric obstacle we give sufficient conditions for both existence and non-existence of an eigenvalue. We also prove that in the case of a thin obstacle, parallel to the axis of the cylinder, there always exists an eigenvalue.