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Main Author: Jafari, Amir
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2504.10763
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author Jafari, Amir
author_facet Jafari, Amir
contents We briefly review the recent developments in magnetohydrodynamics, which in particular deal with the evolution of magnetic fields in turbulent plasmas. We especially emphasize (i) the necessity of renormalizing equations of motion in turbulence where velocity and magnetic fields become Hölder singular; (ii) the breakdown of Laplacian determinism (spontaneous stochasticity) for turbulent magnetic fields; and (iii) the possibility of eliminating the notion of magnetic field lines, using instead magnetic path lines as trajectories of Alfvenic wave-packets. These methodologies are then exemplified with their application to the problem of magnetic reconnection -- rapid change in magnetic field pattern that accelerates plasma -- a ubiquitous phenomenon in astrophysics and laboratory plasmas. The necessity of smoothing out rough velocity and magnetic fields on a finite scale L implies that magnetohydrodynamic equations should be regarded as effective field theories with running parameters depending upon the scale L.
format Preprint
id arxiv_https___arxiv_org_abs_2504_10763
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Effective Field Theories in Magnetohydrodynamics
Jafari, Amir
Plasma Physics
High Energy Astrophysical Phenomena
We briefly review the recent developments in magnetohydrodynamics, which in particular deal with the evolution of magnetic fields in turbulent plasmas. We especially emphasize (i) the necessity of renormalizing equations of motion in turbulence where velocity and magnetic fields become Hölder singular; (ii) the breakdown of Laplacian determinism (spontaneous stochasticity) for turbulent magnetic fields; and (iii) the possibility of eliminating the notion of magnetic field lines, using instead magnetic path lines as trajectories of Alfvenic wave-packets. These methodologies are then exemplified with their application to the problem of magnetic reconnection -- rapid change in magnetic field pattern that accelerates plasma -- a ubiquitous phenomenon in astrophysics and laboratory plasmas. The necessity of smoothing out rough velocity and magnetic fields on a finite scale L implies that magnetohydrodynamic equations should be regarded as effective field theories with running parameters depending upon the scale L.
title Effective Field Theories in Magnetohydrodynamics
topic Plasma Physics
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2504.10763