6 papers
Corrections to the RPA Dielectric Function Induced by Fluctuations in the Momentum Distribution
Girish S. Setlur, Yia-Chung Chang
In this article, we introduce a new dielectric function that is different even from the generalised RPA, first introduced in cond-mat/9810043, in that it pays attention to fluctuat…
Exact Single-Particle Green Functions of Fermi Systems Without Using Bosonization or Are Hartree-Fock and Random Phase Approximations 'Controlled Approximations' ?
Girish S. Setlur, Yia-Chung Chang
In this article, we revisit the question of the validity of Hartree-Fock and random-phase approximations. We show that there is a connection between the two and while the RPA as it…
Computing Number Fluctuations
Girish S. Setlur, Yia-Chung Chang
Here we try and delienate the properties of the function that corresponds to fluctuations in the momentum distribution. The quantity denoted by is quite an interesti…
Energy Levels of Multielectron Atoms using the Sea-boson Method
Girish S. Setlur, Yia-Chung Chang
In this article, we study an antithesis of the homogeneous Fermi system (jellium model) namely a single multielectron atom using the sea-boson approach. This system in addition to…
Parent-bilinear Sea-boson Correspondence with Spin
Girish S. Setlur, Yia-Chung Chang
This is a sort of tutorial where we present many of the tedious details involved in deriving the correspondence between the number conserving product of two fermi/bose fields with…
Exact Optical Dielectric Function of a Nearly Homogeneous Solid
Girish S. Setlur, Yia-Chung Chang
Based on an exactly solvable model of a nearly homogeneous solid (jellium+phonons), we compute the optical dielectric function exactly at zero temperature in any number of spatial…