Now the prominent Lee-Yang theorem (or Physical Review 87, 410, 1952) has almost become a standard ingredient of any comprehensive statistical mechanics textbook.
If the volume tends to infinity, some complex roots of the grand canonical partition function may converge to some points $z_0,z_1,z_2,\dots$ on the real axis. Thus these $\{ z_n \}$ divide the complex plane into some isolated phases. According to the singularity near the $\{z_n\}$ every two neighbouring phases may have phase transition phenomena occurring.
Here comes my question. Considering three phases surrounding a triple point in a phase diagram, they can transit to each other (just think about water). Since the neighbourhood along the real axis consists of only two possibilities, I wonder if this theory could account for a description of the triple point. And what is the connection between the neighbourhood of patches on the complex plane and the neighbourhood of phases in a phase diagram?
This post imported from StackExchange Physics at 2023-11-12 18:19 (UTC), posted by SE-user xiaohuamao