Many Body Aspects of Parity Non-conservation in Heavy Atoms

We review calculations on parity non-conserving E1 matrix elements for transitions of experimental interest in heavy atoms. We find agreement between different methods in Cs and Tl but a more complex situation in Bi. Here there is satisfactory consistency at the single particle level using the dipole length operator but significant modifications are found in going beyond the approximation. While more calculations are required, it is felt that the outlook for a reliable calculation is good.