English
Related papers

Related papers: Do observations prove that cosmological neutrinos …

200 papers

Relic neutrinos from the Big Bang decoupled from the hot plasma predominantly in helicity eigenstates. Their subsequent propagation through gravitational inhomogeneities of the Universe alters the helicities of both Dirac and Majorana…

High Energy Physics - Phenomenology · Physics 2021-11-01 Gordon Baym , Jen-Chieh Peng

We consider some consequences of the presence of a cosmological lepton asymmetry in the form of neutrinos. Relic neutrino degeneracy enhances the contribution of massive neutrinos to the present energy density of the Universe, and modifies…

High Energy Physics - Phenomenology · Physics 2016-08-25 Julien Lesgourgues , Sergio Pastor

Neutrinos may possibly violate the spin-statistics theorem, and hence obey Bose statistics or mixed statistics despite having spin half. We find the generalized equilibrium distribution function of neutrinos which depends on a single…

Astrophysics · Physics 2010-12-09 A. D. Dolgov , S. H. Hansen , A. Yu. Smirnov

Probably the most promising way of detecting cosmic neutrinos is measuring the mechanical force exerted by elastic scattering of cosmic neutrinos from macroscopic targets. The expected acceleration is $\sim 10^{-23} cm/s^2$ for Dirac…

Astrophysics · Physics 2009-10-31 C. Hagmann

We have determined the dispersion relation of a neutrino test particle propagating in the cosmic neutrino background. Describing the relic neutrinos and antineutrinos from the hot big bang as a dense medium, a matter potential or refractive…

High Energy Physics - Phenomenology · Physics 2016-03-09 J. S. Diaz , F. R. Klinkhamer

We solve coupled momentum-dependent Boltzmann equations for the phase space distribution of cosmic relic particles, without resorting to approximations of assuming kinetic equilibrium or neglecting backscattering or elastic interactions.…

High Energy Physics - Phenomenology · Physics 2022-06-09 Kalle Ala-Mattinen , Matti Heikinheimo , Kimmo Kainulainen , Kimmo Tuominen

The detection of a sterile neutrino could constitute the first observation of a particle that could have been produced before Big-Bang Nucleosynthesis (BBN), and could provide information about the yet untested pre-BBN era. The cosmological…

High Energy Physics - Phenomenology · Physics 2020-06-19 Graciela B. Gelmini , Philip Lu , Volodymyr Takhistov

The intersection of the cosmic and neutrino frontiers is a rich field where much discovery space still remains. Neutrinos play a pivotal role in the hot big bang cosmology, influencing the dynamics of the universe over numerous decades in…

Neutrinos can play an important role in the evolution of the Universe, modifying some of the cosmological observables. In this contribution we summarize the main aspects of cosmological relic neutrinos and we describe how the precision of…

High Energy Physics - Phenomenology · Physics 2012-12-27 Julien Lesgourgues , Sergio Pastor

The late-time entropy production by the massive particle decay induces the various cosmological effects in the early epoch and modify the standard scenario. We investigate the thermalization process of the neutrinos after the entropy…

Astrophysics · Physics 2016-08-30 M. Kawasaki , K. Kohri , Naoshi Sugiyama

In the standard Big Bang cosmology the canonical value for the ratio of relic neutrinos to CMB photons is 9/11. Within the framework of the Standard Model of particle physics there are small corrections, in sum about 1%, due to slight…

Astrophysics · Physics 2009-10-30 Robert E. Lopez , Scott Dodelson , Andrew Heckler , Michael S. Turner

We derive general constraints on the relic abundances of a long-lived particle which mainly decays into a neutrino (and something else) at cosmological time scales. Such an exotic particle may show up in various particle-physics models…

High Energy Physics - Phenomenology · Physics 2008-11-26 Toru Kanzaki , Masahiro Kawasaki , Kazunori Kohri , Takeo Moroi

Massive neutrinos were the first proposed, and remain the most natural, particle candidate for the dark matter. In the absence of firm laboratory evidence for neutrino mass, considerations of the formation of large scale structure in the…

High Energy Physics - Phenomenology · Physics 2011-02-16 Subir Sarkar

In this paper, we analyze the cosmological evolution, allowed parameter space, and observational prospects for a dark sector consisting of thermally produced pseudo-Dirac fermions with a small mass splitting, coupled to the Standard Model…

High Energy Physics - Phenomenology · Physics 2021-09-02 Mariana Carrillo González , Natalia Toro

The expansion history and thermal physical process that happened in the early Universe before big bang nucleosynthesis (BBN) remains relatively unconstrained by observations. Low reheating temperature universes with normalcy temperatures of…

High Energy Physics - Phenomenology · Physics 2023-12-07 Kevork N. Abazajian , Helena García Escudero

Low-energy neutrinos from the cosmic background are captured by objects in the sky that contain material susceptible of single beta decay. Neutrons, which compose most of a neutron star, capture low-energy neutrinos from the cosmic neutrino…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 Beatriz Hernandez-Molinero , Raul Jimenez , Carlos Peña Garay

The primordial abundances of the light nuclides produced by Big Bang Nucleosynthesis (BBN) during the first 20 minutes in the evolution of the Universe are sensitive to the universal density of baryons and to the expansion rate of the early…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gary Steigman

For the first time the antineutrino spectrum formed as a result of neutron and tritium decays during the epoch of primordial nucleosynthesis is calculated. This spectrum is a non-thermal increase in addition to the standard cosmic neutrino…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-05 Alexandre V. Ivanchik , Vlad Yu. Yurchenko

We study the impact of assumptions made about the neutrino mass ordering on cosmological parameter estimation with the purpose of understanding whether in the future it will be possible to infer the specific neutrino mass distribution from…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-15 Maria Archidiacono , Steen Hannestad , Julien Lesgourgues

We develop a first-principles formalism to compute the distortion to the relic neutrino density field caused by the peculiar motions of large-scale structures. This distortion slows halos down due to dynamical friction, causes a local…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-14 Caio Nascimento , Marilena Loverde