Refinements of the Eigenstate Thermalization Hypothesis under Local Rotational Invariance via Free Probability

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Vallini, Elisa, Foini, Laura, Pappalardi, Silvia
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917111724507136
author Vallini, Elisa
Foini, Laura
Pappalardi, Silvia
author_facet Vallini, Elisa
Foini, Laura
Pappalardi, Silvia
contents The Eigenstate Thermalization Hypothesis (ETH) was developed as a framework for understanding how the principles of statistical mechanics emerge in the long-time limit of isolated quantum many-body systems. Since then, ETH has shifted the attention towards the study of matrix elements of physical observables in the energy eigenbasis. In this work, we revisit recent developments leading to the formulation of full ETH, a generalization of the original ETH ansatz that accounts for multi-point correlation functions. Using tools from free probability, we explore the implications of local rotational invariance, a property that emerges from the statistical invariance of observables under random basis transformations induced by small perturbations of the Hamiltonian. This approach allows us to make quantitative predictions and derive an analytical characterization of subleading corrections to matrix-element correlations, thereby refining the ETH ansatz. Moreover, our analysis links the statistical properties of matrix elements under random basis changes to the empirical averages over energy windows that are usually considered when dealing with a single instance of the ensemble. We validate our analytical predictions through comparison with numerical simulations in non-integrable Floquet systems.
format Preprint
id arxiv_https___arxiv_org_abs_2511_23217
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Refinements of the Eigenstate Thermalization Hypothesis under Local Rotational Invariance via Free Probability
Vallini, Elisa
Foini, Laura
Pappalardi, Silvia
Statistical Mechanics
High Energy Physics - Theory
Quantum Physics
The Eigenstate Thermalization Hypothesis (ETH) was developed as a framework for understanding how the principles of statistical mechanics emerge in the long-time limit of isolated quantum many-body systems. Since then, ETH has shifted the attention towards the study of matrix elements of physical observables in the energy eigenbasis. In this work, we revisit recent developments leading to the formulation of full ETH, a generalization of the original ETH ansatz that accounts for multi-point correlation functions. Using tools from free probability, we explore the implications of local rotational invariance, a property that emerges from the statistical invariance of observables under random basis transformations induced by small perturbations of the Hamiltonian. This approach allows us to make quantitative predictions and derive an analytical characterization of subleading corrections to matrix-element correlations, thereby refining the ETH ansatz. Moreover, our analysis links the statistical properties of matrix elements under random basis changes to the empirical averages over energy windows that are usually considered when dealing with a single instance of the ensemble. We validate our analytical predictions through comparison with numerical simulations in non-integrable Floquet systems.
title Refinements of the Eigenstate Thermalization Hypothesis under Local Rotational Invariance via Free Probability
topic Statistical Mechanics
High Energy Physics - Theory
Quantum Physics
url https://arxiv.org/abs/2511.23217