In this paper, we consider Ising models with ferromagnetic pair interactions. We prove that the Ursell functions u2k satisfy: (- 1) k-1u2k is increasing in each interaction. As an application, we prove a 1983 conjecture by Nishimori and Griffiths about the partition function of the Ising model with complex external field h: its closest zero to the origin (in the variable h) moves towards the origin as an arbitrary interaction increases.
|Original language||English (US)|
|Journal||Communications In Mathematical Physics|
|State||Accepted/In press - 2023|
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Mathematical Physics