Planck 2015 results. XIX. Constraints on primordial magnetic fields
read the original abstract
We compute and investigate four types of imprint of a stochastic background of primordial magnetic fields (PMFs) on the cosmic microwave background (CMB) anisotropies: the impact of PMFs on the CMB spectra; the effect on CMB polarization induced by Faraday rotation; the impact of PMFs on the ionization history; magnetically-induced non-Gaussianities; and the magnetically-induced breaking of statistical isotropy. Overall, Planck data constrain the amplitude of PMFs to less than a few nanogauss. In particular, individual limits coming from the analysis of the CMB angular power spectra, using the Planck likelihood, are $B_{1\,\mathrm{Mpc}}< 4.4$ nG (where $B_{1\,\mathrm{Mpc}}$ is the comoving field amplitude at a scale of 1 Mpc) at 95% confidence level, assuming zero helicity, and $B_{1\,\mathrm{Mpc}}< 5.6$ nG for a maximally helical field.For nearly scale-invariant PMFs we obtain $B_{1\,\mathrm{Mpc}}<2.0$ nG and $B_{1\,\mathrm{Mpc}}<0.9$ nG if the impact of PMFs on the ionization history of the Universe is included. From the analysis of magnetically-induced non-Gaussianity we obtain three different values, corresponding to three applied methods, all below 5 nG. The constraint from the magnetically-induced passive-tensor bispectrum is $B_{1\,\mathrm{Mpc}}< 2.8$ nG. A search for preferred directions in the magnetically-induced passive bispectrum yields $B_{1\,\mathrm{Mpc}}< 4.5$ nG, whereas the the compensated-scalar bispectrum gives $B_{1\,\mathrm{Mpc}}< 3$ nG. The analysis of the Faraday rotation of CMB polarization by PMFs uses the Planck power spectra in $EE$ and $BB$ at 70 GHz and gives $B_{1\,\mathrm{Mpc}}< 1380$ nG. In our final analysis, we consider the harmonic-space correlations produced by Alfv\'en waves, finding no significant evidence for the presence of these waves. Together, these results comprise a comprehensive set of constraints on possible PMFs with Planck data.
This paper has not been read by Pith yet.
Forward citations
Cited by 13 Pith papers
-
Primordial Black Holes from Vector-Induced Curvature Perturbations Sourced by Primordial Magnetic Fields
Vector modes from primordial magnetic fields remain constant in a kination epoch and source second-order curvature perturbations scaling as P_R(k) ∝ k^{-5}, sufficient for PBH dark matter abundance in a Ratra-type mag...
-
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 uGM...
-
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 masse...
-
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 ...
-
Graviton Floor
Photon-to-graviton conversion in blazar jets dominates a new graviton background that sets a floor for high-frequency GW detectors, analogous to the neutrino floor.
-
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.
-
Revisiting constraints on primordial vector modes and implications for sourced magnetic fields and observed $EB$ power spectrum
Updated constraints on neutrino-sustained primordial vector modes imply magnetic fields too weak to seed observations and cannot reproduce the EB power spectrum while satisfying parity-even limits.
-
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 ob...
-
Dark QCD Origin of the NANOGrav Signal and Self-Interacting Dark Matter
A dark QCD model with a first-order phase transition at 5-6 MeV produces the NANOGrav SGWB amplitude while supplying self-interacting dark matter via a 40 GeV baryon and 20-50 MeV dilaton, linked by entropy dilution.
-
Unraveling the Imprints of Fluctuation-dynamo on the Intracluster Medium with the SKA
MHD simulations indicate that SKA-Mid Band 5a can detect filamentary polarized emission from ICM magnetic fields at high resolution and sensitivity, allowing inference of turbulence driving scales.
-
Gravitational Waves from Post-Inflationary Magnetism: Direct and Scalar-Induced Contributions
In a post-inflationary magnetogenesis scenario with time-dependent gauge couplings, magnetic anisotropic stress dominates peak GW amplitude while scalar-induced terms matter on larger scales, both showing f^3 infrared...
-
Detectors for CLASS-W2: The second 90 GHz telescope of the Cosmology Large Angular Scale Surveyor
A new 296-detector 90 GHz TES bolometer array for CLASS achieves uniform properties, 16 μK√s NET, 0.37 optical efficiency, and a 41% mapping speed boost after addressing blue-leak radiation.
-
Lectures on Reheating after Inflation
Lecture notes providing a generic introduction to reheating after inflation, covering its theoretical, phenomenological, and observational aspects.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.