Oh wow, thank you for the clarification! If I understand it correctly then, the divergent compressibility is a consequence of Bose-Einstein condensation? It de

Oh wow, thank you for the clarification! If I understand it correctly then, the divergent compressibility is a consequence of Bose-Einstein condensation? It definitely is exciting to see light show this effect. I wonder how much the difference between light and matter (due to very different dispersion relations) has an influence on the BEC properties like compressibility. I guess that's what they are trying to find out.