Non-extensivity of the chemical potential of polymer melts J. P. Wittmer, A. Johner, A. Cavallo, P. Beckrich, F. Crevel and J. Baschnagel Eur. Phys. J. E, 31 3 (2010) 229-237 Published online: 09 March 2010 DOI: 10.1140/epje/i2010-10571-9