Related papers: Exploring neutrino interactions in light of presen…
Neutrinos are expected to freestream (i.e. not interact with anything) since they decouple in the early Universe at a temperature $T\sim 2~{\rm MeV}$. However, there are many relevant particle physics scenarios that can make neutrinos…
In the standard model neutrinos are assumed to have streamed across the Universe since they last scattered at the weak decoupling epoch when the temperature of the standard-model plasma was ~MeV. The shear stress of free-streaming neutrinos…
A cosmological scenario in which the onset of neutrino free streaming in the early Universe is delayed until close to the epoch of matter-radiation equality has been shown to provide a good fit to some cosmic microwave background (CMB)…
Perturbations in the cosmic neutrino background produce a characteristic phase shift in the acoustic oscillations imprinted in the anisotropies of the cosmic microwave background (CMB), providing a unique observational probe of neutrino…
We investigate signatures of neutrino scattering in the Cosmic Microwave Background (CMB) and matter power spectra, and the extent to which present cosmological data can distinguish between a free streaming or tightly coupled fluid of…
Some cosmic microwave background (CMB) data allow a cosmological scenario in which the free streaming of neutrinos is delayed until close to matter-radiation equality. Interestingly, recent analyses have revealed that large-scale structure…
New physics in the neutrino sector might be necessary to address anomalies between different neutrino oscillation experiments. Intriguingly, it also offers a possible solution to the discrepant cosmological measurements of $H_0$ and…
We present updated constraints on the free-streaming nature of cosmological neutrinos from cosmic microwave background (CMB) power spectra, baryonic acoustic oscillation data, and local measurements of the Hubble constant. Specifically, we…
We explore a self-interacting neutrino cosmology in which neutrinos experience a delayed onset of free-streaming. We use the effective field theory of large-scale structure (LSS) to model matter distribution on mildly non-linear scales…
The cosmic neutrino background and other light relics leave distinct imprints in the cosmic microwave background anisotropies through their gravitational influence. Since neutrinos decoupled from the primordial plasma about one second after…
We perform a new study of future sensitivities of galaxy redshift surveys to the free-streaming effect caused by neutrino masses, adding the information on cosmological parameters from measurements of primary anisotropies of the cosmic…
Standard cosmology predicts that prior to matter-radiation equality about 41% of the energy density was in free-streaming neutrinos. In many beyond Standard Model scenarios, however, the amount and free-streaming nature of this component is…
Precision data from cosmology suggest neutrinos stream freely and hence interact very weakly around the epoch of recombination. We study this issue in a simple framework where neutrinos recouple instantaneously and stop streaming freely at…
We perform a comprehensive study of cosmological constraints on non-standard neutrino self-interactions using cosmic microwave background (CMB) and baryon acoustic oscillation data. We consider different scenarios for neutrino…
Cosmological observations are becoming increasingly sensitive to the effects of light particles in the form of dark radiation (DR) at the time of recombination. The conventional observable of effective neutrino number, $N_{\rm eff}$, is…
The cosmic microwave background (CMB) has proven to be an invaluable tool for studying the properties and interactions of neutrinos, providing insight not only into the sum of neutrino masses but also the free streaming nature of neutrinos…
New interactions of neutrinos can stop them from free streaming even after the weak interaction freeze-out. This results in a phase shift in the cosmic microwave background (CMB) acoustic peaks which can alleviate the Hubble tension. In…
The connection between cosmological observations and neutrino physics is discussed in detail. Neutrinos decouple from thermal contact in the early Universe at a temperature of order 1 MeV which coincides with the temperature where light…
If active neutrinos undergo non-standard (`secret') interactions (NS$\nu$I) the cosmological evolution of the neutrino fluid might be altered, leaving an imprint in cosmological observables. We use the latest publicly available CMB data…
Neutrinos with Standard Model interactions free-stream in the early Universe, leaving a distinct phase shift in the pattern of baryon acoustic oscillations (BAO). When isolated, this phase shift allows one to robustly infer the presence of…