Effective inter-band coupling in MgB 2 due to anharmonic phonons. Abstract We investigate the origin of the inter-band coupling in M gB 2 by focusing on its unusual phononic features, namely, the strong anharmonicity of the phonons and the presence of both linear and quadratic electron-phonon interactions of the Su-Schrieffer-Heeger (SSH) type. The bare electronic Hamil-tonian has two bands wit...

Starting from the tight-binding dielectric matrix in the random phase approximation we examine the collective modes and electron-hole excitations in a two-band electronic system. For long wavelengths (q → 0), for which most of the analysis is carried out, the properties of the collective modes are closely related to the symmetry of the atomic orbitals involved in the tight-binding states. In in...

This paper reports an information-theoretic analysis of the dependencies that exist between curvelet coefficients. We show that strong dependencies exist in local intra-band micro-neighborhoods, and that the shape of these neighborhoods is highly anisotropic. With this respect, it is found that the two immediately adjacent neighbors that lie in a direction orthogonal to the orientation of the s...

Synchronization of gamma oscillations among brain regions is relevant for dynamically organizing communication among neurons to support cognitive and perceptual processing, including attention orienting. Recent research has demonstrated that inter-regional synchronization in the gamma-band is modulated by theta rhythms during cortical processing. It has been proposed that such cross-frequency d...