The paper calculates multifrequency angular power spectra of the 21 cm line for models with primordial magnetic fields of strength 4 nG and spectral indices -2.9 and -2.5, then estimates signal-to-noise ratios for uGMRT, MeerKAT and SKA1-MID.
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The origin, evolution and signatures of primordial magnetic fields
11 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
The universe is magnetized on all scales probed so far. On the largest scales, galaxies and galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten kpc. Recent observational evidence suggests that even the intergalactic medium in voids could host a weak $\sim 10^{-16}$ Gauss magnetic field, coherent on Mpc scales. An intriguing possibility is that these observed magnetic fields are a relic from the early universe, albeit one which has been subsequently amplified and maintained by a dynamo in collapsed objects. We review here the origin, evolution and signatures of primordial magnetic fields. After a brief summary of magnetohydrodynamics in the expanding universe, we turn to magnetic field generation during inflation and other phase transitions. We trace the linear and nonlinear evolution of the generated primordial fields through the radiation era, including viscous effects. Sensitive observational signatures of primordial magnetic fields on the cosmic microwave background, including current constraints from Planck, are discussed. After recombination, primordial magnetic fields could strongly influence structure formation, especially on dwarf galaxy scales. The resulting signatures on reionization, the redshifted 21 cm line, weak lensing and the Lyman-$\alpha$ forest are outlined. Constraints from radio and $\gamma$-ray astronomy are summarized. Astrophysical batteries and the role of dynamos in reshaping the primordial field are briefly considered. The review ends with some final thoughts on primordial magnetic fields.
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Lattice simulations show that Schwinger currents saturate gauge-field production in axion inflation, yielding universal conductivity and magnetic-field values at the onset of strong backreaction.
Coupling dark photons to standard photons enables adequate primordial magnetogenesis without strong-coupling or backreaction issues.
A self-consistent Parker bound on magnetic monopoles is derived using the galactic mean-field dynamo eigenmode and turbulent field seeding and acceleration, producing modified flux limits at low and intermediate masses that are robust to primordial magnetic fields.
Multi-phase inflation with chiral vector interactions generates amplified primordial magnetic fields that induce a detectable circularly polarized gravitational-wave background.
Proposes that axion-photon conversion in pre-CMB helical magnetic fields imprints detectable V-mode polarization in the CMB, allowing CLASS 40 GHz observations to constrain ALP masses 10^{-10} to 10^{-8} eV and their photon coupling under optimistic nG field assumptions.
Inflationary magnetic fields induce curvature perturbations that form ultralight PBHs, generating a stochastic GW background with model-specific features.
Electromagnetism is reformulated from relativistic fluid dynamics via pull-back of differential forms from matter space, imposing kinematical constraints from the absence of four-forms and identifying a preferred frame where spacetime field strength matches the intrinsic matter-space two-form.
Primordial magnetic fields enhance low-mass halo abundance at Cosmic Dawn, advancing Lyman-alpha coupling, X-ray heating and reionization and imprinting detectable signatures on global and fluctuating 21-cm signals observable by HERA and SKA.
Finite conductivity of the plasma suppresses parametric resonance amplification of electromagnetic fields from ultralight pseudoscalar dark matter, making it impossible to generate magnetic fields of sufficient strength in cosmic voids for observationally viable couplings.
Superposition of static galactic magnetic dipoles is screened by intergalactic plasma and cannot account for lower bounds on magnetic fields in cosmic voids from blazar gamma-ray data.
citing papers explorer
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Effects of primordial magnetic fields on 21 cm multifrequency angular power spectra
The paper calculates multifrequency angular power spectra of the 21 cm line for models with primordial magnetic fields of strength 4 nG and spectral indices -2.9 and -2.5, then estimates signal-to-noise ratios for uGMRT, MeerKAT and SKA1-MID.
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Schwinger effect in axion inflation on a lattice
Lattice simulations show that Schwinger currents saturate gauge-field production in axion inflation, yielding universal conductivity and magnetic-field values at the onset of strong backreaction.
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Dark photon -- Assisted Primordial Magnetogenesis
Coupling dark photons to standard photons enables adequate primordial magnetogenesis without strong-coupling or backreaction issues.
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Self-Consistent Parker Bound on Magnetic Monopoles
A self-consistent Parker bound on magnetic monopoles is derived using the galactic mean-field dynamo eigenmode and turbulent field seeding and acceleration, producing modified flux limits at low and intermediate masses that are robust to primordial magnetic fields.
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Chiral gravitational waves from multi-phase magnetogenesis
Multi-phase inflation with chiral vector interactions generates amplified primordial magnetic fields that induce a detectable circularly polarized gravitational-wave background.
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Probing Axion-Photon conversion via circular polarization imprints in the CMB $V$-mode observations
Proposes that axion-photon conversion in pre-CMB helical magnetic fields imprints detectable V-mode polarization in the CMB, allowing CLASS 40 GHz observations to constrain ALP masses 10^{-10} to 10^{-8} eV and their photon coupling under optimistic nG field assumptions.
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The Magnetic Origin of Primordial Black Holes: Ultralight PBHs and Secondary GWs
Inflationary magnetic fields induce curvature perturbations that form ultralight PBHs, generating a stochastic GW background with model-specific features.
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Electromagnetism from relativistic fluid dynamics
Electromagnetism is reformulated from relativistic fluid dynamics via pull-back of differential forms from matter space, imposing kinematical constraints from the absence of four-forms and identifying a preferred frame where spacetime field strength matches the intrinsic matter-space two-form.
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Primordial Magnetic Fields at Cosmic Dawn: 21-cm Forecasts with HERA and SKA
Primordial magnetic fields enhance low-mass halo abundance at Cosmic Dawn, advancing Lyman-alpha coupling, X-ray heating and reionization and imprinting detectable signatures on global and fluctuating 21-cm signals observable by HERA and SKA.
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Suppressed Magnetogenesis from Ultralight Dark Matter due to Finite Conductivity
Finite conductivity of the plasma suppresses parametric resonance amplification of electromagnetic fields from ultralight pseudoscalar dark matter, making it impossible to generate magnetic fields of sufficient strength in cosmic voids for observationally viable couplings.
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On the contribution of galaxies to the magnetic field in cosmic voids
Superposition of static galactic magnetic dipoles is screened by intergalactic plasma and cannot account for lower bounds on magnetic fields in cosmic voids from blazar gamma-ray data.