Bayesian critical points in classical lattice models

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Nahum, Adam, Jacobsen, Jesper Lykke
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866913771925012480
author Nahum, Adam
Jacobsen, Jesper Lykke
author_facet Nahum, Adam
Jacobsen, Jesper Lykke
contents The Boltzmann distribution encodes our subjective knowledge of the configuration in a classical lattice model, given only its Hamiltonian. If we acquire further information about the configuration from measurement, our knowledge is updated according to Bayes' theorem. We examine the resulting "conditioned ensembles", finding that they show many new phase transitions and new renormalization-group fixed points. (Similar conditioned ensembles also describe "partial quenches" in which some of the system's degrees of freedom are instantaneously frozen, while the others continue to evolve.) After describing general features of the replica field theories for these problems, we analyze the effect of measurement on illustrative critical systems, including: critical Ising and Potts models, which show surprisingly rich phase diagrams, with RG fixed points at weak, intermediate, and infinite measurement strength; various models involving free fields, XY spins, or flux lines in 2D or 3D; and geometrical models such as polymers or clusters. We make connections with quantum dynamics, in particular with "charge sharpening" in 1D, by giving a formalism for measurement of classical stochastic processes: e.g. we give a purely hydrodynamic derivation of the known effective field theory for charge sharpening. We discuss qualitative differences between RG flows for the above measured systems, described by $N\to 1$ replica limits, and those for disordered systems, described by $N\to 0$ limits. In addition to discussing measurement of critical states, we give a unifying treatment of a family of inference problems for non-critical states. These are related to the Nishimori line in the phase diagram of the random-bond Ising model, and are relevant to various quantum error correction problems. We describe distinct physical interpretations of conditioned ensembles and note interesting open questions.
format Preprint
id arxiv_https___arxiv_org_abs_2504_01264
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Bayesian critical points in classical lattice models
Nahum, Adam
Jacobsen, Jesper Lykke
Statistical Mechanics
Disordered Systems and Neural Networks
Quantum Physics
The Boltzmann distribution encodes our subjective knowledge of the configuration in a classical lattice model, given only its Hamiltonian. If we acquire further information about the configuration from measurement, our knowledge is updated according to Bayes' theorem. We examine the resulting "conditioned ensembles", finding that they show many new phase transitions and new renormalization-group fixed points. (Similar conditioned ensembles also describe "partial quenches" in which some of the system's degrees of freedom are instantaneously frozen, while the others continue to evolve.) After describing general features of the replica field theories for these problems, we analyze the effect of measurement on illustrative critical systems, including: critical Ising and Potts models, which show surprisingly rich phase diagrams, with RG fixed points at weak, intermediate, and infinite measurement strength; various models involving free fields, XY spins, or flux lines in 2D or 3D; and geometrical models such as polymers or clusters. We make connections with quantum dynamics, in particular with "charge sharpening" in 1D, by giving a formalism for measurement of classical stochastic processes: e.g. we give a purely hydrodynamic derivation of the known effective field theory for charge sharpening. We discuss qualitative differences between RG flows for the above measured systems, described by $N\to 1$ replica limits, and those for disordered systems, described by $N\to 0$ limits. In addition to discussing measurement of critical states, we give a unifying treatment of a family of inference problems for non-critical states. These are related to the Nishimori line in the phase diagram of the random-bond Ising model, and are relevant to various quantum error correction problems. We describe distinct physical interpretations of conditioned ensembles and note interesting open questions.
title Bayesian critical points in classical lattice models
topic Statistical Mechanics
Disordered Systems and Neural Networks
Quantum Physics
url https://arxiv.org/abs/2504.01264