Criticality without Temperature in an Ising Spin System
Abstract
Criticality in the Ising model is conventionally generated by Hamiltonian dynamics and controlled by temperature. Here we show that critical like behavior can emerge in an Ising system whose dynamics is completely independent of the Ising Hamiltonian and contains no temperature like parameter. We introduce an adaptive cluster dynamics in which spin connectivity is controlled by a local quiet time variable, the time elapsed since a spin was last updated. The Ising Hamiltonian enters only as an observable characterizing the resulting configurations. As the parameter α, controlling the connectivity strength, is varied, the system undergoes spontaneous symmetry breaking accompanied by strong collective fluctuations. The cluster size distribution develops an extended power law regime, terminated by a small finite size hump at the largest scales, while the Ising energy exhibits a singular response to the variation of α. These results show that memory dependent connectivity alone can generate collective critical behavior, revealing a route to nonequilibrium criticality without energy based dynamics.
Related
- Cluster Representation of Renormalization Group Transformations and a Rigorous Proof for Convergence of the RG-Flow of the Ising Model to Trivial Fixed Points away from Criticality
- Free energy of non-convex multi-species spin glasses with centered Ising spins
- Berry--Esseen Bounds for High-Temperature Ising Models
- Free energy of non-convex multi-species Ising spin glasses with external fields
- A Simple Approach to the Complexity of Mean Field Ising Spin Glasses
BibTeX
@misc{kakalis2026criticality,
title = {{Criticality without Temperature in an Ising Spin System}},
author = {Christos Kakalis and Fotios K. Diakonos},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.33361},
eprint = {2609.33361},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.33361},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Criticality without Temperature in an Ising Spin System
AU - Christos Kakalis
AU - Fotios K. Diakonos
PY - 2026
DA - 2026/09/27
PB - arXiv
DO - 10.48550/arxiv.2609.33361
UR - https://arxiv.org/abs/2609.33361
AB - Criticality in the Ising model is conventionally generated by Hamiltonian dynamics and controlled by temperature. Here we show that critical like behavior can emerge in an Ising system whose dynamics is completely independent of the Ising Hamiltonian and contains no temperature like parameter. We introduce an adaptive cluster dynamics in which spin connectivity is controlled by a local quiet time variable, the time elapsed since a spin was last updated. The Ising Hamiltonian enters only as an observable characterizing the resulting configurations. As the parameter α, controlling the connectivity strength, is varied, the system undergoes spontaneous symmetry breaking accompanied by strong collective fluctuations. The cluster size distribution develops an extended power law regime, terminated by a small finite size hump at the largest scales, while the Ising energy exhibits a singular response to the variation of α. These results show that memory dependent connectivity alone can generate collective critical behavior, revealing a route to nonequilibrium criticality without energy based dynamics.
ER -