Saved in:
Bibliographic Details
Main Authors: Angelini, Maria Chiara, Palazzi, Saverio, Parisi, Giorgio, Rizzo, Tommaso
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2403.01171
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910720059244544
author Angelini, Maria Chiara
Palazzi, Saverio
Parisi, Giorgio
Rizzo, Tommaso
author_facet Angelini, Maria Chiara
Palazzi, Saverio
Parisi, Giorgio
Rizzo, Tommaso
contents In statistical physics, one of the standard methods to study second order phase transitions is the renormalization group that usually leads to an expansion around the corresponding fully connected solution. Unfortunately, often in disordered models, some important finite dimensional second-order phase transitions are qualitatively different or absent in the corresponding fully connected model: in such cases the standard expansion fails. Recently, a new method, the $M$-layer one, has been introduced that performs an expansion around a different soluble mean field model: the Bethe lattice one. This new method has been already used to compute the upper critical dimension $D_U$ of different disordered systems such as the Random Field Ising model or the Spin glass model with field. If then one wants to go beyond and construct an expansion around $D_U$ to understand how critical quantities get renormalized, the actual computation of all the numerical factors is needed. This next step has still not been performed, being technically more involved. In this paper we perform this computation for the ferromagnetic Ising model without quenched disorder, in finite dimensions: we show that, at one-loop order inside the $M$-layer approach, we recover the continuum quartic field theory and we are able to identify the coupling constant $g$ and the other parameters of the theory, as a function of macroscopic and microscopic details of the model such as the lattice spacing, the physical lattice dimension and the temperature. This is a fundamental step that will help in applying in the future the same techniques to more complicated systems, for which the standard field theoretical approach is impracticable.
format Preprint
id arxiv_https___arxiv_org_abs_2403_01171
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Bethe $M$-layer construction on the Ising model
Angelini, Maria Chiara
Palazzi, Saverio
Parisi, Giorgio
Rizzo, Tommaso
Statistical Mechanics
In statistical physics, one of the standard methods to study second order phase transitions is the renormalization group that usually leads to an expansion around the corresponding fully connected solution. Unfortunately, often in disordered models, some important finite dimensional second-order phase transitions are qualitatively different or absent in the corresponding fully connected model: in such cases the standard expansion fails. Recently, a new method, the $M$-layer one, has been introduced that performs an expansion around a different soluble mean field model: the Bethe lattice one. This new method has been already used to compute the upper critical dimension $D_U$ of different disordered systems such as the Random Field Ising model or the Spin glass model with field. If then one wants to go beyond and construct an expansion around $D_U$ to understand how critical quantities get renormalized, the actual computation of all the numerical factors is needed. This next step has still not been performed, being technically more involved. In this paper we perform this computation for the ferromagnetic Ising model without quenched disorder, in finite dimensions: we show that, at one-loop order inside the $M$-layer approach, we recover the continuum quartic field theory and we are able to identify the coupling constant $g$ and the other parameters of the theory, as a function of macroscopic and microscopic details of the model such as the lattice spacing, the physical lattice dimension and the temperature. This is a fundamental step that will help in applying in the future the same techniques to more complicated systems, for which the standard field theoretical approach is impracticable.
title Bethe $M$-layer construction on the Ising model
topic Statistical Mechanics
url https://arxiv.org/abs/2403.01171