Publication Date:
2017-02-24
Description:
We consider the spectrum of the almost Mathieu operator \({H_\alpha}\) with frequency \({\alpha}\) and in the case of the critical coupling. Let an irrational \({\alpha}\) be such that \({|\alpha - p_n/q_n| 〈 c q_n^{-\varkappa}}\) , where \({p_n/q_n}\) , \({n=1,2,\ldots}\) , are the convergents to \({\alpha}\) , and \({c}\) , \({\varkappa}\) are positive absolute constants, \({\varkappa 〈 56}\) . Assuming certain conditions on the parity of the coefficients of the continued fraction of \({\alpha}\) , we show that the central gaps of \({H_{p_n/q_n}}\) , \({n=1,2,\ldots}\) , are inherited as spectral gaps of \({H_\alpha}\) of length at least \({c'q_n^{-\varkappa/2}}\) , \({c' 〉 0}\) .
Print ISSN:
0010-3616
Electronic ISSN:
1432-0916
Topics:
Mathematics
,
Physics
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