Scaling approach to existence of long cycles in Casimir boxes

Mathieu Beau (1, 2)

1 CPT - Centre de Physique Théorique - UMR 6207
2 CPT - Centre de Physique Théorique - UMR 7332

We analyse the concept of generalized Bose-Einstein condensation (g-BEC), known since 1982 for the perfect Bose gas (PBG) in the Casimir (or anisotropic) boxes. Our aim is to establish a relation between this phenomenon and two concepts: the concept of long cycles and the Off-Diagonal-Long-Range-Order (ODLRO), which are usually considered as some adequate way to describe the standard BEC on the ground state for the cubic boxes. First we show that these three criterions are equivalent in this latter case. Then, basing on a scaling approach, we revise formu- lation of these concepts to prove that the classification of the g-BEC into three types I,II,III, implies a hierarchy of long cycles (depending on their size scale) as well as a hierarchy of ODLRO which depends on the coherence length of the condensate.

Mots clés: Scaling; Generalized Bose-Einstein condensation; (Long) Cycles; Off-Diagonal-Long-Range-Order (ODLRO); perfect Bose gas; Casimir boxes; Scaling.

Domaines: Physique mathématique [math-ph]; Physique mathématique [math-ph]

Mathieu Beau. Scaling approach to existence of long cycles in Casimir boxes. Journal of Physics A: Mathematical and Theoretical, 2009, 43 (23), pp.235204. ⟨hal-00332745v3⟩