Yang-Lee zeros for an urn model for the separation of sand.
We apply the Yang-Lee theory of phase transitions to an urn model for the separation of sand. The effective partition function of this nonequilibrium system can be expressed as a polynomial of the size-dependent effective fugacity z. Numerical calculations show that in the thermodynamic limit the zeros of the effective partition function are located on the unit circle in the complex z plane. In the complex plane of the actual control parameter, certain roots converge to the transition point of the model. Thus, the Yang-Lee theory can be applied to a wider class of nonequilibrium systems than those considered previously.
Bena
I
I
Department of Physics, University of Geneva, CH 1211 Geneva 4, Switzerland.
Coppex
F
F
Droz
M
M
Lipowski
A
A