| | |
| | |
Stat |
Members: 3645 Articles: 2'501'711 Articles rated: 2609
20 April 2024 |
|
| | | |
|
Article overview
| |
|
The inverse spectral problem for first order systems on the half line | Matthias Lesch
; Mark M. Malamud
; | Date: |
7 May 1998 | Journal: | In: Differential operators and related topics, Vol. I (Odessa, 1997), 199--238, Oper. Theory Adv. Appl., 117, Birkhaeuser, Basel, 2000 | Subject: | Spectral Theory; Classical Analysis and ODEs MSC-class: 34A25 (Primary), 34L (Secondary) | math.SP math.CA | Affiliation: | Humboldt-University at Berlin) and Mark M. Malamud (Donetsk | Abstract: | On the half line $[0,infty)$ we study first order differential operators of the form $B 1/i d/(dx) + Q(x)$, where $B:=mat{B_1}{0}{0}{-B_2}$, $B_1,B_2in M(n,C)$ are self--adjoint positive definite matrices and $Q:R_+ o M(2n,C)$, $R_+:=[0,infty)$, is a continuous self-adjoint off-diagonal matrix function. We determine the self-adjoint boundary conditions for these operators. We prove that for each such boundary value problem there exists a unique matrix spectral function $sigma$ and a generalized Fourier transform which diagonalizes the corresponding operator in $L^2_{sigma}(R, C)$. We give necessary and sufficient conditions for a matrix function $sigma$ to be the spectral measure of a matrix potential $Q$. Moreover we present a procedure based on a Gelfand-Levitan type equation for the determination of $Q$ from $sigma $. Our results generalize earlier results of M. Gasymov and B. Levitan. We apply our results to show the existence of $2n imes 2n$ Dirac systems with purely absolute continuous, purely singular continuous and purely discrete spectrum of multiplicity $p$, where $1le p le n$ is arbitrary. | Source: | arXiv, math.SP/9805033 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |