This volume contains the lectures of the third and fourth Poincare Seminar, both held in 2003. The third one is on Bose-Einstein Condensation: it covers the phy... » 

This volume contains the lectures of the third and fourth Poincare Seminar, both held in 2003. The third one is on Bose-Einstein Condensation: it covers the physics of superfluid liquid helium as well as the recently discovered atomic Bose-Einstein condensates. The fourth one concentrates on Entropy. «