Critical point fluctuations: Finite size and global charge conservation effects

Understand

We investigate simultaneous effects of finite system size and global charge conservation on thermal fluctuations in the vicinity of a critical point.

• For that we consider a finite interacting system which exchanges particles with a finite reservoir (thermostat), comprising a statistical ensemble that is distinct from the common canonical and grand canonical ensembles.
• As a particular example the van der Waals model is used.
• The global charge conservation effects strongly influence the cumulants of particle number distribution when the system size is comparable to that of the reservoir.