English
Related papers

Related papers: Consistent $N_{\rm eff}$ fitting in big bang nucle…

200 papers

The cosmic energy density in the form of radiation before and during Big Bang Nucleosynthesis (BBN) is typically parameterized in terms of the effective number of neutrinos N_eff. This quantity, in case of no extra degrees of freedom,…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 G. Mangano , G. Miele , S. Pastor , O. Pisanti , S. Sarikas

Big-bang nucleosynthesis (BBN) probes the cosmic mass-energy density at temperatures $\sim 10$ MeV to $\sim 100$ keV. Here, we consider the effect of a cosmic matter-like species that is non-relativistic and pressureless during BBN. Such a…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-18 Tsung-Han Yeh , Keith A. Olive , Brian D. Fields

A new evaluation of the constraint on the number of light neutrino species (N_nu) from big bang nucleosynthesis suggests a discrepancy between the predicted light element abundances and those inferred from observations, unless the inferred…

High Energy Physics - Phenomenology · Physics 2009-04-13 N. Hata , R. J. Scherrer , G. Steigman , D. Thomas , T. P. Walker , S. Bludman , P. Langacker

We consider Big Bang nucleosynthesis and the cosmic microwave background when both the neutrino temperature and neutrino number are allowed to vary from their standard values. The neutrino temperature is assumed to differ from its standard…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Richard Galvez , Robert J. Scherrer

In this work we investigate the impact of two phenomenological Beyond the Standard Model (BSM) scenarios concerning the role of neutrinos in the early universe: non-standard neutrino interactions (NSI) and non-unitary three-neutrino mixing.…

High Energy Physics - Phenomenology · Physics 2025-10-13 Gabriela Barenboim , Stefano Gariazzo , Alberto Sánchez-Vargas

We report the results on Big Bang Nucleosynthesis (BBN) based on an updated code, with accuracy of the order of 0.1% on He4 abundance, compared with the predictions of other recent similar analysis. We discuss the compatibility of the…

Astrophysics · Physics 2009-10-31 S. Esposito , G. Mangano , G. Miele , O. Pisanti

We use Big Bang Nucleosynthesis (BBN) data in order to impose constraints on the exponent of Barrow entropy. The latter is an extended entropy relation arising from the incorporation of quantum-gravitational effects on the black-hole…

General Relativity and Quantum Cosmology · Physics 2021-02-19 John D. Barrow , Spyros Basilakos , Emmanuel N. Saridakis

We study the impact of light GeV-scale heavy neutral leptons (HNLs) on Big Bang nucleosynthesis (BBN) in the neutrino-extended Standard Model Effective Field Theory ($\nu$SMEFT). We show that, based on very general considerations, BBN…

High Energy Physics - Phenomenology · Physics 2026-02-16 Pieter Braat , Jordy de Vries , Jelle Groot , Julian Y. Günther , Juraj Klarić

A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the standard model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, \eta, corresponding to the inferred primordial…

Astrophysics · Physics 2007-05-23 Brian Fields , Subir Sarkar

Coherent forward scattering processes by neutrino-scalar nonstandard interactions (SNSI) induce an effective neutrino mass. In the Early Universe, a large neutrino effective mass restricts the production of neutrinos. The SNSI effect is…

High Energy Physics - Phenomenology · Physics 2021-02-26 Jorge Venzor , Abdel Pérez-Lorenzana , Josue De-Santiago

Cosmological determinations of the number of relativistic neutrino species, $N^{ }_{\rm eff}$, are becoming increasingly accurate, and further improvements are expected both from CMB and BBN data. Given this context, we update the…

High Energy Physics - Phenomenology · Physics 2026-02-16 M. Escudero , G. Jackson , M. Laine , S. Sandner

The Hubble parameter inferred from cosmic microwave background observations is consistently lower than that from local measurements, which could hint towards new physics. Solutions to the Hubble tension typically require a sizable amount of…

High Energy Physics - Phenomenology · Physics 2021-06-16 Guo-yuan Huang , Werner Rodejohann

A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the Standard Model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, $\eta$, corresponding to the inferred primordial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Brian D. Fields , Paolo Molaro , Subir Sarkar

I present a review of Big Bang Nucleosynthesis, concentrating on the statistical analysis of theoretical uncertainties, and on systematic errors in observed abundances. Both have important implications for constraints on the amount of…

Astrophysics · Physics 2008-02-03 Lawrence M. Krauss

Neutrino non-standard interactions (NSI) with electrons, predicted in many extended theoretical models of particle physics, are known to alter the picture of neutrino decoupling from the cosmic plasma. We update previous analyses of…

High Energy Physics - Phenomenology · Physics 2026-03-02 Stefano Gariazzo , Jaume Moncho , Sergio Pastor , Ofelia Pisanti

The effective number of relativistic neutrino species is a fundamental probe of the early Universe and its measurement represents a key constraint on many scenarios beyond the Standard Model of Particle Physics. In light of this, an…

High Energy Physics - Phenomenology · Physics 2023-12-21 Mattia Cielo , Miguel Escudero , Gianpiero Mangano , Ofelia Pisanti

One of the major goals of future Cosmic Microwave Background measurements is the accurate determination of the effective number of neutrinos $N_{\rm eff}$. Reaching an experimental sensitivity of $\Delta N_{\rm eff} = 0.013$ could indeed…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Ludovico Capparelli , Eleonora Di Valentino , Alessandro Melchiorri , Jens Chluba

We derive here a robust bound on the effective number of neutrinos from constraints on primordial nucleosynthesis yields of deuterium and helium. In particular, our results are based on very weak assumptions on the astrophysical…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-13 Gianpiero Mangano , Pasquale D. Serpico

Recently we presented a simple method for determining the correlated uncertainties of the light element abundances expected from big bang nucleosynthesis, which avoids the need for lengthy Monte Carlo simulations. We now extend this…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. Lisi , Subir Sarkar , F. L. Villante

A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the Standard Model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, $\eta$, corresponding to the inferred primordial…

Astrophysics · Physics 2011-02-09 Brian Fields , Subir Sarkar
‹ Prev 1 2 3 10 Next ›