We calculate the pair distribution function, g(r), in a two-dimensional
electron gas and derive a simple analytical expression for its value at the
origin as a function of rs. Our approach is based on solving the
Schr\"{o}dinger equation for the two-electron wave function in an appropriate
effective potential, leading to results that are in good agreement with Quantum
Monte Carlo data and with the most recent numerical calculations of g(0). [C.
Bulutay and B. Tanatar, Phys. Rev. B {\bf 65}, 195116 (2002)] We also show that
the spin-up spin-down correlation function at the origin, g↑↓(0), is mainly independent of the degree of spin polarization of
the electronic system.Comment: 5 figures, pair distribution dependence with distance is calculate