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Related papers: Free-energy bounds for hierarchical spin models

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We consider two non-mean-field models of structural glasses built on a hierarchical lattice. First, we consider a hierarchical version of the random energy model (HREM), and we prove the existence of the thermodynamic limit and…

Mathematical Physics · Physics 2014-09-09 Michele Castellana

In the last five decades, mean-field neural-networks have played a crucial role in modelling associative memories and, in particular, the Hopfield model has been extensively studied using tools borrowed from the statistical mechanics of…

Disordered Systems and Neural Networks · Physics 2024-09-17 Elena Agliari , Adriano Barra , Pierluigi Bianco , Alberto Fachechi , Diego Pallara

This work proves an upper bound for the free energy of the Sherrington-Kirkpatrick model and its generalizations in terms of the Thouless-Anderson-Palmer (TAP) energy. The result applies to models with spherical or Ising spins and any mixed…

Probability · Mathematics 2022-04-05 David Belius

We introduce a Random Energy Model on a hierarchical lattice where the interaction strength between variables is a decreasing function of their mutual hierarchical distance, making it a non-mean field model. Through small coupling series…

Statistical Mechanics · Physics 2014-09-09 Michele Castellana , Aurelien Decelle , Silvio Franz , Marc Mezard , Giorgio Parisi

We evaluate the high temperature limit of the free energy of spin glasses on the hypercube with Hamiltonian $H_N(\sigma) = \sigma^T J \sigma$, where the coupling matrix $J$ is drawn from certain symmetric orthogonally invariant ensembles.…

Probability · Mathematics 2016-01-27 Bhaswar B. Bhattacharya , Subhabrata Sen

By using renormalization-group (RG) methods, we study a non-mean-field model of a spin glass built on a hierarchical lattice, the hierarchical Edwards-Anderson model in a magnetic field. We investigate the spin-glass transition in a field…

Disordered Systems and Neural Networks · Physics 2015-03-03 Michele Castellana , Carlo Barbieri

We consider the quantum Sherrington-Kirkpatrick (SK) spin-glass model with transverse field and provide a formula for its free energy in the thermodynamic limit, valid for all inverse temperatures $\beta>0$. To characterize the free energy,…

Probability · Mathematics 2020-01-01 Arka Adhikari , Christian Brennecke

We study a variant of the Sherrington-Kirkpatrick (S-K) spin glass model with external field, where the random symmetric couplings matrix does not consist of i.i.d. entries but is instead orthogonally invariant in law. For sufficiently high…

Probability · Mathematics 2024-05-01 Zhou Fan , Yihong Wu

We present a numerical study of an Ising spin glass with hierarchical interactions - the hierarchical Edwards-Anderson model with an external magnetic field (HEA). We study the model with Monte Carlo (MC) simulations in the mean-field (MF)…

Disordered Systems and Neural Networks · Physics 2015-03-10 Michele Castellana , Giorgio Parisi

We analyze the free energy and the overlaps in the 2-spin spherical Sherrington Kirkpatrick spin glass model with an external field for the purpose of understanding the transition between this model and the one without an external field. We…

Disordered Systems and Neural Networks · Physics 2021-05-26 Jinho Baik , Elizabeth Collins-Woodfin , Pierre Le Doussal , Hao Wu

We introduce a Sherrington-Kirkpatrick spin-glass model with the addition of elastic degrees of freedom. The problem is formulated in terms of an effective four-spin Hamiltonian in the pressure ensemble, which can be treated by the replica…

Disordered Systems and Neural Networks · Physics 2009-04-30 D. B. Liarte , S. R. Salinas , C. S. O. Yokoi

We study the phenomenon of the locking of the order parameter (or synchronization) in spin glasses at low temperatures. When two systems with independent disorders are coupled, their overlaps become similar. A crucial question is how this…

Disordered Systems and Neural Networks · Physics 2026-05-05 Silvio Franz , Giorgio Parisi , Federico Ricci-Tersenghi

The spherical Sherrington-Kirkpatrick model is a spherical mean field model for spin glass. We consider the fluctuations of the free energy at arbitrary non-critical temperature for the 2-spin model with no magnetic field. We show that in…

Probability · Mathematics 2016-09-21 Jinho Baik , Ji Oon Lee

We introduce a mean field spin glass model with gaussian distribuited spins and pairwise interactions, whose couplings are drawn randomly from a normal gaussian distribution too. We completely control the main thermodynamical properties of…

Mathematical Physics · Physics 2012-05-18 Adriano Barra , Giuseppe Genovese , Francesco Guerra , Daniele Tantari

We study numerically various properties of the free energy barriers in the Edwards-Anderson model of spin glasses in the low-temperature region both in three and four spatial dimensions. In particular, we investigated the dependence of…

Disordered Systems and Neural Networks · Physics 2018-07-23 A. Maiorano , G. Parisi

We discuss the mean-field theory of spin-glass models with frustrated long-range random spin exchange. We analyze the reasons for breakdown of the simple mean-field theory of Sherrington and Kirkpatrick. We relate the replica-symmetry…

Disordered Systems and Neural Networks · Physics 2015-06-24 Václav Janiš

We present a simple strategy in order to show the existence and uniqueness of the infinite volume limit of thermodynamic quantities, for a large class of mean field disordered models, as for example the Sherrington-Kirkpatrick model, and…

Disordered Systems and Neural Networks · Physics 2009-11-07 Francesco Guerra , Fabio L. Toninelli

We study analytically the equilibrium properties of the spherical hierarchical model in the presence of random fields. The expression for the critical line separating a paramagnetic from a ferromagnetic phase is derived. The critical…

Disordered Systems and Neural Networks · Physics 2014-11-18 Fernando L. Metz , Jacopo Rocchi , Pierfrancesco Urbani

We identify a special class of multi-species spin glass models: ones in which the species proportions serve to ''balance'' out the interaction strengths. For this class, we prove a free energy lower bound that does not require any convexity…

Probability · Mathematics 2025-07-28 Erik Bates , Youngtak Sohn

We show that the free energy in the mixed $p$-spin models of spin glasses does not superconcentrate in the presence of external field, which means that its variance is of the order suggested by the Poincar\'e inequality. This complements…

Probability · Mathematics 2017-06-09 Wei-Kuo Chen , Partha Dey , Dmitry Panchenko
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