The Fisher-Widom line  (not to be confused with the Widom line) is a locus in the pressure-temperature plane and in the density-temperature plane, such that for thermodynamic states of the fluid that lie on one side of the locus, the decay of the correlation function is oscillatory, and in those that lie on the other side it is monotonic.
- C. Vega, L. F. Rull, and S. Lago "Location of the Fisher-Widom line for systems interacting through short-ranged potentials", Physical Review E 51 pp. 3146-3155 (1995)
- P. Tarazona, E. Chacón and E. Velasco "The Fisher-Widom line for systems with low melting temperature", Molecular Physics 101 pp. 1595-1603 (2003)