On the spectrum of the discrete inhomogeneous wave equation, and vibrations of a discrete string
Sbornik. Mathematics, Tome 75 (1993) no. 2, pp. 317-331
Cet article a éte moissonné depuis la source Math-Net.Ru
Explicit analytic expressions are found for the spectrum and solutions of the discrete, inhomogeneous wave equation $$ {d^2 q_n \over d t^2}-a_n(q_{n+1}-2q_n+q_{n-1})+\delta_n q_n=0 $$ with boundary conditions $q_0(t) = q_N(t) = 0$, where $n=0,\,1,\,\dots,\,N$, $a_n>0$, and $\delta_n \geqslant 0$. As a corollary a solution is given of the classical problem of finding an explicit analytic expression describing the vibrations of a string all the mass of which is concentrated at a finite number of equidistant points, which was the object of detailed study by Euler, D'Alembert, D. Bernoulli, Lagrange, Sturm, Routh, and others, who gave a solution of it in the particular case where the masses of all points are the same. The general solution of the problem turns out to be connected with a generalized quaternion algebra and properties of certain of its ideals, and this connection is used in an essential way in the proofs of the theorems.
@article{SM_1993_75_2_a1,
author = {L. D. Pustyl'nikov},
title = {On the spectrum of the~discrete inhomogeneous wave equation, and vibrations of a~discrete string},
journal = {Sbornik. Mathematics},
pages = {317--331},
year = {1993},
volume = {75},
number = {2},
language = {en},
url = {http://geodesic.mathdoc.fr/item/SM_1993_75_2_a1/}
}
L. D. Pustyl'nikov. On the spectrum of the discrete inhomogeneous wave equation, and vibrations of a discrete string. Sbornik. Mathematics, Tome 75 (1993) no. 2, pp. 317-331. http://geodesic.mathdoc.fr/item/SM_1993_75_2_a1/
[1] Lagranzh P., Analiticheskaya mekhanika, t. 1, GONTI NKTP SSSR, 1938
[2] Gantmakher F. R., Lektsii po analiticheskoi mekhanike, Nauka, M., 1966
[3] Gantmakher F. R., Krein M. G., Ostsillyatsionnye matritsy i yadra i malye kolebaniya mekhanicheskikh sistem, Gostekhizdat, M., 1950
[4] Babakov I. M., Teoriya kolebanii, Nauka, M., 1965 | MR | Zbl
[5] Shafarevich I. R., “Osnovnye ponyatiya algebry”, Sovremennye problemy matematiki, 11, VINITI, M., 1986, 5–288