Primordial magnetic field amplification from turbulent reheating

We analyze the possibility of primordial magnetic field amplification by a stochastic large scale kinematic dynamo during reheating. We consider a charged scalar field minimally coupled to gravity. During inflation this field is assumed to be in its vacuum state. At the transition to reheating the s...

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Detalles Bibliográficos
Autores principales:	Calzetta, E., Kandus, A.
Formato:	JOUR
Materias:	Cosmic magnetic fields theory Magnetohydrodynamics
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_14757516_v2010_n8_p_Calzetta
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_14757516_v2010_n8_p_Calzetta
record_format	dspace
spelling	todo:paper_14757516_v2010_n8_p_Calzetta2023-10-03T16:18:40Z Primordial magnetic field amplification from turbulent reheating Calzetta, E. Kandus, A. Cosmic magnetic fields theory Magnetohydrodynamics We analyze the possibility of primordial magnetic field amplification by a stochastic large scale kinematic dynamo during reheating. We consider a charged scalar field minimally coupled to gravity. During inflation this field is assumed to be in its vacuum state. At the transition to reheating the state of the field changes to a many particle/anti-particle state. We characterize that state as a fluid flow of zero mean velocity but with a stochastic velocity field. We compute the scale-dependent Reynolds number Re(k), and the characteristic times for decay of turbulence, td and pair annihilation ta, finding ta ≪ td. We calculate the rms value of the kinetic helicity of the flow over a scale Γ and show that it does not vanish. We use this result to estimate the amplification factor of a seed field from the stochastic kinematic dynamo equations. Although this effect is weak, it shows that the evolution of the cosmic magnetic field from reheating to galaxy formation may well be more complex than as dictated by simple flux freezing. © 2010 IOP Publishing Ltd and SISSA. Fil:Calzetta, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Kandus, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14757516_v2010_n8_p_Calzetta
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Cosmic magnetic fields theory Magnetohydrodynamics
spellingShingle	Cosmic magnetic fields theory Magnetohydrodynamics Calzetta, E. Kandus, A. Primordial magnetic field amplification from turbulent reheating
topic_facet	Cosmic magnetic fields theory Magnetohydrodynamics
description	We analyze the possibility of primordial magnetic field amplification by a stochastic large scale kinematic dynamo during reheating. We consider a charged scalar field minimally coupled to gravity. During inflation this field is assumed to be in its vacuum state. At the transition to reheating the state of the field changes to a many particle/anti-particle state. We characterize that state as a fluid flow of zero mean velocity but with a stochastic velocity field. We compute the scale-dependent Reynolds number Re(k), and the characteristic times for decay of turbulence, td and pair annihilation ta, finding ta ≪ td. We calculate the rms value of the kinetic helicity of the flow over a scale Γ and show that it does not vanish. We use this result to estimate the amplification factor of a seed field from the stochastic kinematic dynamo equations. Although this effect is weak, it shows that the evolution of the cosmic magnetic field from reheating to galaxy formation may well be more complex than as dictated by simple flux freezing. © 2010 IOP Publishing Ltd and SISSA.
format	JOUR
author	Calzetta, E. Kandus, A.
author_facet	Calzetta, E. Kandus, A.
author_sort	Calzetta, E.
title	Primordial magnetic field amplification from turbulent reheating
title_short	Primordial magnetic field amplification from turbulent reheating
title_full	Primordial magnetic field amplification from turbulent reheating
title_fullStr	Primordial magnetic field amplification from turbulent reheating
title_full_unstemmed	Primordial magnetic field amplification from turbulent reheating
title_sort	primordial magnetic field amplification from turbulent reheating
url	http://hdl.handle.net/20.500.12110/paper_14757516_v2010_n8_p_Calzetta
work_keys_str_mv	AT calzettae primordialmagneticfieldamplificationfromturbulentreheating AT kandusa primordialmagneticfieldamplificationfromturbulentreheating
_version_	1782026461286236160

Primordial magnetic field amplification from turbulent reheating

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