Signatures of Bulk Neutrinos in the Early Universe

Abstract

Neutrino masses and quantum gravity are strong reasons to extend the standard model of particle physics. A large extra dimension can be motivated by quantum gravity and can explain the small neutrino masses with new singlet states that propagate in the bulk. In such a case, a Kaluza-Klein tower of sterile neutrinos emerges. We revisit constraints on towers of sterile neutrinos that come from cosmological observables such as the effective number of noninteracting relativistic species and the dark matter density. These limits generically rule out micron-sized extra dimensions. We explore the weakening of these constraints to accommodate an extra dimension close to the micron size by assuming that the universe reheated after inflation to a low temperature. We discuss how such a possibility can be distinguished in the event of a positive signal in a cosmological observable.

15 pages, 2 figures v2: references added, matches version published in Physical Review D

References in corpus (34)

• The Reactor Antineutrino Anomaly
• The fate of hints: updated global analysis of three-flavor neutrino oscillations
• The Swampland: Introduction and Review
• Sterile neutrino search at NEOS Experiment
• The Dark Dimension and the Swampland
• A Search for Electron Neutrino Transitions to Sterile States in the BEST Experiment
• Long-Exposure NuSTAR Constraints on Decaying Dark Matter in the Galactic Halo
• Origin of Sterile Neutrino Dark Matter via Vector Secret Neutrino Interactions
• Improved Constraints on Sterile Neutrino Mixing from Disappearance Searches in the MINOS, MINOS+, Daya Bay, and Bugey-3 Experiments
• Dirac neutrinos and $N_{\mathrm{eff}}$
• Testing for Large Extra Dimensions with Neutrino Oscillations
• Limits on the Existence of sub-MeV Sterile Neutrinos from the Decay of ${}^7$Be in Superconducting Quantum Sensors
• Baryogenesis from Oscillations of Charmed or Beautiful Baryons
• Dirac neutrinos and $N_{\mathrm{eff}}$ II: the freeze-in case
• Freezing-in hadrophilic dark matter at low reheating temperatures
• Aspects of the Dark Dimension in Cosmology
• Updated constraints on decaying cold dark matter
• Search for sterile neutrino oscillation using RENO and NEOS data
• Large Extra Dimensions and neutrino experiments
• From WIMPs to FIMPs with Low Reheating Temperatures
• Neutrino non-standard interactions meet precision measurements of $N_{\mathrm{eff}}$
• Improved eV-scale Sterile-Neutrino Constraints from the Second KATRIN Measurement Campaign
• Probing the Milky Way's Dark Matter Halo for the 3.5 keV Line
• Constraining new physics scenarios in neutrino oscillations from Daya Bay data
• Towards distinguishing Dirac from Majorana neutrino mass with gravitational waves
• Making the Universe at 20 MeV
• Unraveling the Dirac Neutrino with Cosmological and Terrestrial Detectors
• Low scale Dirac leptogenesis and dark matter with observable $\Delta N_{\mathrm{eff}}$
• Can Neutrino Self-interactions Save Sterile Neutrino Dark Matter?
• Unitarity Bound on Dark Matter in Low-temperature Reheating Scenarios
• Testing Dirac leptogenesis with the cosmic microwave background and proton decay
• Search for Signatures of Sterile Neutrinos with Double Chooz
• A Common Origin for the QCD Axion and Sterile Neutrinos from $SU(5)$ Strong Dynamics
• The BeEST Experiment: Searching for Beyond Standard Model Neutrinos using ${}^7$Be Decay in STJs

Cited by in corpus (2)

• Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the string-theoretical Swampland Programme
• Semianalytic model for decaying dark matter halos