Abstract

We propose a new method of constructing the effective theory for a multicomponent low-dimensional dilute Bose gas. The method is based on obtaining and solving renormalization group equations for all many-body interactions of density-density type in the one-loop approximation. In contrast to the standard approach based on two-body interactions, our method does not rely on the introduction of density-dependent infrared cutoff, and is able to reproduce exactly the leading term in the energy density of the one-dimensional dilute Bose gas, and to obtain the next term with the error of less than 2%.

Key words: ultracold atoms, spinor bosons, low-dimensional Bose gas.