Joint 21-cm and CMB Forecasts for Constraining Self-Interacting Massive Neutrinos

Abstract

Self-interacting neutrinos provide an intriguing extension to the Standard Model, motivated by both particle physics and cosmology. Recent cosmological analyses suggest a bimodal posterior for the coupling strength $G_{\mathrm{eff}}$, favoring either strong or moderate interactions. These interactions modify the scale-dependence of the growth of cosmic structures, leaving distinct imprints on the matter power spectrum at small scales, $k>0.1{\mathrm{Mpc}}^{-1}$. For the first time, we explore how the 21-cm power spectrum from the cosmic dawn and the dark ages can constrain the properties of self-interacting, massive neutrinos. The effects of small-scale suppression and enhancement in the matter power spectrum caused by self-interacting neutrinos propagate to the halo mass function, shaping the abundance of small- and intermediate-mass halos. It is precisely these halos that host the galaxies responsible for driving the evolution of the 21-cm signal during the cosmic dawn. We find that HERA at its design sensitivity can improve upon existing constraints on $G_{\mathrm{eff}}$ and be sensitive to small values of the coupling, beyond the reach of current and future CMB experiments. Crucially, we find that the combination of HERA and CMB-S4 can break parameter degeneracies, significantly improving the sensitivity to $G_{\mathrm{eff}}$ over either experiment alone. Finally, we investigate the prospects of probing neutrino properties with futuristic Lunar interferometers, accessing the astrophysics-free 21-cm power spectrum during the dark ages. The capability of probing small scales of these instruments will allow us to reach a percent-level constraint on the neutrino self-coupling.

28 pages, 13 fugures, v2 accepted for publication in PRD

References in corpus (18)

• Observation of electron-antineutrino disappearance at Daya Bay
• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Massive neutrinos and cosmology
• Massloss of galaxies due to a UV-background
• 21 cm fluctuations from inhomogeneous X-ray heating before reionization
• Feedback-regulated star formation and escape of LyC photons from mini-haloes during reionisation
• Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array
• Interacting neutrinos in cosmology: exact description and constraints
• Updated constraints on massive neutrino self-interactions from cosmology in light of the $H_0$ tension
• Boltzmann hierarchy for interacting neutrinos I: formalism
• An Effective Model for the Cosmic-Dawn 21-cm Signal
• The Difference PDF of 21-cm Fluctuations: A Powerful Statistical Tool for Probing Cosmic Reionization
• Low-mass suppression of the satellite luminosity function due to the supersonic baryon--cold-dark-matter relative velocity
• Revisiting the impact of neutrino mass hierarchies on neutrino mass constraints in light of recent DESI data
• Large-scale Array for Radio Astronomy on the Farside
• 21cmSense v2: A modular, open-source 21cm sensitivity calculator
• The limits of cosmology: role of the Moon

Cited by in corpus (2)

• Directly Probing Neutrino Interactions through CMB Phase Shift Measurements
• Impostor Among $\nu$s: Dark Radiation Masquerading as Self-Interacting Neutrinos