Correlations in a one-dimensional Bose gas

Abstract

We study the correlation effects in a one-dimensional Bose gas with repulsive delta-function interaction. The correlation effects are described by a local-field correction which takes into account the short-range correlations. We find that the ground state energy is in good agreement with the exact result up to intermediate coupling strengths, showing an improvement over the Bogoliubov and other related approximations. The velocity of sound, the static structure factor, and pair-correlation function are also calculated within the present approximation. ͓S0163-1829͑99͒00314-8͔

Probability distributions of line lattices in random media from the 1D Bose gas

“…( 46) in the limit n → 0 gives the disorder averaged free energy of lines in a random environment following Eqs. (10) and (41). Expanding g n (x) to first order in n, we get from Eq.…”

“…This is an important constraint on the various approximative methods in use for the Bose gas. Recently, different self-consistent approximations have been used to calculate the ground state energy based on a so-called localfield correction approach [40,41]. In view of the fact that the two approaches give different signs for the γ 7/2 term in Eq.…”

Correlation effects in a one-dimensional electron gas with short-range interaction

“…This is an improvement over the STLS scheme which show agreement with the exact ground state energy for small values of the coupling strength. Our calculations are motivated by similar improvements for the 1D interacting boson system, when the VS approach is used [12].…”