Vortex phase diagram and two-dimensional bosons

We study the phase diagram of the flux lines using the mapping to two-dimen sional bosons interacting via the Yukawa potential in the hypernetted-chain approximation. The pair-correlation function, static structure factor, and spectrum of the excited energies are calculated over a wide range of the p arameter. These quantities are used for studying the freezing transition fr om the entangled vortex liquid into the Abrikosov lattice. The resulting B- T phase diagram is in good agreement with the known estimates for the vorte x lattice phase diagram and the Monte Carlo simulations.