Equation of state for hard sphere fluids with and without Kac tails

E. Trizac ¹, I. Pagonabarraga ²

American Journal of Physics 76 (2008) 777

In this note, we propose a simple derivation of the one dimensional hard rod equation of state, with and without a Kac tail (appended long range and weak potential). The case of hard spheres in higher dimension is also addressed and it is shown there that our arguments –which avoid any mathematical complication– allow to recover the virial form of the equation of state in a direct way.

• 1. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
  CNRS : UMR8626 – Université Paris XI – Paris Sud
• 2. Departament de Física Fonamental, Universitat de Barcelona,
  Departament de Física Fonamental, Universitat de Barcelona