REVIEW 10 cited by
On the detection of a cosmic dawn signal in the radio background
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
abstract
The astrophysics of cosmic dawn, when star formation commenced in the first collapsed objects, is predicted to be revealed as spectral and spatial signatures in the cosmic radio background at long wavelengths. The sky-averaged redshifted 21-cm absorption line of neutral hydrogen is a probe of cosmic dawn. The line profile is determined by the evolving thermal state of the gas, radiation background, Lyman-$\alpha$ radiation from stars scattering off cold primordial gas and the relative populations of the hyperfine spin levels in neutral hydrogen atoms. We report a radiometer measurement of the spectrum of the radio sky in the 55--85~MHz band, which shows that the profile found by Bowman et al. in data taken with the Experiment to Detect the Global Epoch of Reionization Signature (EDGES) low-band instrument is not of astrophysical origin; their best-fitting profile is rejected with 95.3\% confidence. The profile was interpreted to be a signature of cosmic dawn; however, its amplitude was substantially higher than that predicted by standard cosmological models. Explanations for the amplitude of the profile included non-standard cosmology, additional mechanisms for cooling the baryons, perhaps via interactions with millicharged dark matter and an excess radio background at redshifts beyond 17. Our non-detection bears out earlier concerns and suggests that the profile found by Bowman et al. is not evidence for new astrophysics or non-standard cosmology.
Forward citations
Cited by 10 Pith papers
-
A Sequentially-Valid Reanalysis of DESI's Dynamical Dark Energy Signal
An anytime-valid e-process reanalysis shows DESI's dynamical dark energy evidence is a fragile LRG2-bin, specification-dependent signal that does not survive a trials correction.
-
Impact of numerical stability in Bayesian noise wave calibration on global 21-cm experiments
Near-collinearity of noise-source and load design-matrix columns makes REACH’s five-parameter Bayesian calibration non-reproducible; a four-parameter Chebyshev fit with hot-load T_NS(ν) recovery and spike masking stab...
-
When galaxies burst II. Implications of enhanced burstiness for the 21-cm Cosmic Dawn signal
Bursty star formation adds a shot-noise-like term to the Cosmic Dawn 21-cm power spectrum, boosting it by factors of a few at the Wouthuysen-Field trough and strongly on small scales at high redshift.
-
Cosmological constraints on TeV-scale dark matter subcomponents decaying between recombination and reionisation
Future global 21-cm observations could beat CMB limits on TeV-scale decaying dark matter for lifetimes ≳10^15 s, especially for decays into neutrinos.
-
A New Boundary Condition on Reionization
A zero-lag Pearson correlation between 21-cm and line-intensity maps is predicted to drop sharply at ionized fractions of 1-10%, providing a novel marker for the onset of reionization.
-
Excess Radiation from Axion-Photon Conversion
Resonant conversion of axion-like particles into photons in stochastic magnetic fields can produce an f^-2 radio excess matching ARCADE-2 and deepen the 21cm absorption trough seen by EDGES.
-
The Impact of Population III.1 Flash Reionization for CMB Polarization and Thomson Scattering Optical Depth
An early 'Pop III.1 Flash' reionization phase shifts CMB polarization power from l<8 to l>8, allowing a higher optical depth τ≈0.08–0.09 while staying closer to Planck's low-l EE data than a standard tanh reionization model.
-
NANOGrav 15-year gravitational-wave signals from binary supermassive black-holes seeded by primordial black holes, and implications for the origins of Little Red Dots
A PBH abundance of 10^-14–10^-12 of CDM, with seed masses 1–10^3 M_sun, is fitted to the NANOGrav 15-year background via SMBH mergers, consistent with 21-cm limits.
-
Axion-Photon Conversion in FLRW with Primordial Magnetic Fields: Explaining the Radio Excess
Resonant conversion of axion-like particles into photons in nanogauss primordial magnetic fields is claimed to explain both the ARCADE2 radio excess and the EDGES 21-cm trough for axion masses near 10^-14 to 10^-12 eV.
-
Cosmology with HI
A review chapter collecting the equations, data, and forecasts for using neutral hydrogen, through the 21 cm and Lyman-alpha lines, to measure the Universe.
Discussion (0). Continue with ORCID to comment.