Citation
Zhu, Yunfeng (1996) The Lyapunov exponents for Schrodinger operators and Jacobi matrices with slowly oscillating potentials. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd09022005082236
Abstract
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In the first part, we study the onedimensional halfline Schrodinger operator [...] (1) with 0 < [...] < 1. For each [...], let [...] denote the unique selfadjoint realization of [...] on [...] with boundary condition at 0 given by [...] = 0.
By studying the integrated density of states, we prove the existence of the Lyapunov exponent and the Thouless formula for (1). This yields an explicit formula for these Lyapunov exponents. By applying rank one perturbation theory, we also obtain some spectral consequences. Our main results are the following.
Theorem. Let [...] = [...] and [...] = [...]. Then for all [...], where [...] is the resonance set for (1) which has both Lebesgue measure zero and Hausdorff dimension zero, we have [...] = [...] where [...] is the Lyapunov exponent for [...], and [...] is the integrated density of states for [...].
Theorem. For all [...], where [...] is the resonance set for (1) which has both Lebesgue measure zero and Hausdorff dimension zero, the operator [...] in (1) has Lyapunov behavior with the Lyapunov exponent given by [...] = [...] (2)
Theorem. For [...] (with respect to Lebesgue measure), [...] has dense pure point spectrum on (1,1), and the eigenfunction of [...] to all eigenvalues [...] (1,1) decay like [...] at [...] for almost every [...], where [...] is the Lyapunov exponent for (1) which is given by (2).
Theorem. For [...], the singular continuous part, [...], of the spectral measure [...] for [...] is supported on a Hausdorff dimension zero set.
In the second part, we extend the above arguments to the Jacobi matrix on [...] which is a discrete analog of the Schrodinger operator (1). Let [...] = [...] (3) with [...] < 2 and 0 < [...] < 1.
Similarly, by studying the integrated density of states for (3), we can prove the existence of the Lyapunov exponents and the Thouless formula for (3). Then, we can compute an explicit formula for these Lyapunov exponents. By applying rank one perturbation theory again, we can also obtain some interesting spectral consequences for [...]. We have the following theorems.
Theorem. There exists a Lebesgue measure zero and Hausdorff dimension zero set [...], which we call the resonance set for (3). For all [...] has Lyapunov behavior with the Lyapunov exponent given by [...] = [...] (4)
Theorem. For almost all [...] < 2 (with respect to Lebesgue measure), [...] has dense pure point spectrum on [...], and the eigenvectors to all eigenvalues E decay like [...] at infinity, where [...] is the Lyapunov exponent for (3) which is given by (4).
Theorem. For [...], [...], the singular continuous part of the spectral measure [...] for [...], is supported on a Hausdorff dimension zero set.
Item Type:  Thesis (Dissertation (Ph.D.)) 

Degree Grantor:  California Institute of Technology 
Division:  Physics, Mathematics and Astronomy 
Major Option:  Mathematics 
Thesis Availability:  Restricted to Caltech community only 
Research Advisor(s): 

Thesis Committee: 

Defense Date:  21 May 1996 
Record Number:  CaltechETD:etd09022005082236 
Persistent URL:  http://resolver.caltech.edu/CaltechETD:etd09022005082236 
Default Usage Policy:  No commercial reproduction, distribution, display or performance rights in this work are provided. 
ID Code:  3311 
Collection:  CaltechTHESIS 
Deposited By:  Imported from ETDdb 
Deposited On:  06 Sep 2005 
Last Modified:  26 Dec 2012 02:59 
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