Arithmetic Spectral Transitions for the Maryland Model

26 mins 41 secs,  48.81 MB,  MP3  44100 Hz,  249.76 kbits/sec
Share this media item:
Embed this media item:


About this item
Image inherited from collection
Description: Liu, W (Fudan University)
Tuesday 07 April 2015, 15:30-15:55
 
Created: 2015-04-08 18:01
Collection: Periodic and Ergodic Spectral Problems
Publisher: Isaac Newton Institute
Copyright: Liu, W
Language: eng (English)
Distribution: World     (downloadable)
Explicit content: No
Aspect Ratio: 16:9
Screencast: No
Bumper: UCS Default
Trailer: UCS Default
 
Abstract: In this talk, I will give a precise description of spectra of the Maryland model $ (h_{\lambda,\alpha,\theta}u) _n=u_{n+1}+u_{n-1}+ \lambda \tan \pi(\theta+n\alpha)u_n$ for all values of parameters. For Almost Mathieu Operator (H_{\lambda,\alpha,\theta}u) _n=u_{n+1}+u_{n-1}+ \lambda \cos 2\pi(\theta+n\alpha)u_n, the Lyapunov exponent can almost determine its spectral types(A.Avila, S.Jitomirskaya, J.You, Q.Zhou). When turn to Maryland model, I introduce an arithmetically defined index $\delta (\alpha, \theta)$ and show that
for $\alpha\notin\mathbb{Q},$ $\sigma_{sc}(h_{\lambda,\alpha,\theta})=\overline{\{e:\gamma_{\lambda}(e) <\delta (\alpha, \theta) \}}$ and $\sigma_{pp}(h_{\lambda,\alpha,\theta})=\{e:\gamma_{\lambda}(e) \geq \delta (\alpha, \theta) \}$. Since $\sigma_{ac}(h_{\lambda,\alpha,\theta})=\emptyset,$(B.Simon and T.Spencer),this gives complete description of the spectral decomposition for all values of parameters $\lambda,\alpha,\theta$.
This is a joint work with S.Jitomirskaya.
Available Formats
Format Quality Bitrate Size
MPEG-4 Video 640x360    1.94 Mbits/sec 387.93 MB View Download
WebM 640x360    991.75 kbits/sec 193.70 MB View Download
iPod Video 480x270    521.94 kbits/sec 101.88 MB View Download
MP3 * 44100 Hz 249.76 kbits/sec 48.81 MB Listen Download
Auto (Allows browser to choose a format it supports)