Related papers: Constraining The Early-Universe Baryon Density And…
I discuss BBN with nonequilibrium nu_e<->nu_s oscillations in the more general case of non-zero population of nu_s before oscillations delta N_s>0. I calculate He-4 primordial production Y_p(delta N_s) in the presence of nu_e<->nu_s…
Primordial abundances of light elements are sensitive to the physics of the early Universe and can directly constrain cosmological quantities, such as the baryon-to-photon ratio $\eta_{10}$, the baryon density and the number of neutrino…
Big-bang nucleosynthesis is one of the cornerstones of the standard cosmology. For almost thirty years its predictions have been used to test the big-bang model to within a fraction of a second of the bang. The concordance that exists…
A dark radiation term arises as a correction to the energy momentum tensor in the simplest five-dimensional RS-II brane-world cosmology. In this paper we revisit the constraints on dark radiation based upon the newest results for…
We present cosmological parameters measurements from the full combination of DESI DR1 galaxy clustering data described with large-scale structure effective field theory. By incorporating additional datasets (photometric galaxies and CMB…
In the standard hot big bang nucleosynthesis (BBN) model the primordial abundances of H, H2, He3, He4, and Li7, fix the baryon density of the universe, $\Omega_b$, via the baryon-to-photon ratio, $\eta$, for a given Hubble parameter. Recent…
In conventional general relativity, the expansion rate H of a Robertson-Walker universe is related to the energy density by the Friedmann equation. Aside from the present day, the only epoch at which we can constrain the expansion history…
We consider heavy sterile neutrinos $\nu_s$, with mass in the range 10 MeV $\lesssim m_s \lesssim m_{\pi} \sim 135$ MeV, thermally produced in the early universe and freezing out after the QCD phase transition. The existence of these…
We present the results of analysis of constraints on cosmological parameters from cosmic microwave background (CMB) alone and in combination with galaxy cluster baryon fraction assuming inflation--generated adiabatic scalar fluctuations.…
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…
We confirmed the following idea by numerical calculation: The extended structure of baryons may make the nuclear equation of state stiffer at higher density while keeping the compression modulus for normal nuclear matter around its…
Primordial neutrino-antineutrino asymmetries can be constrained through big-bang nucleosynthesis (BBN) relic abundances and cosmic microwave background (CMB) anisotropies, both observables being sensitive to neutrino properties. The latter…
Big-bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB) anisotropy measurements give independent, accurate measurements of the baryon density and can test the framework of the standard cosmology. Early CMB data are consistent…
Observational constraints on the primordial deuterium-to-hydrogen ratio (D/H) can test theories of the early universe and provide constraints on models of big bang nucleosynthesis (BBN). We measure deuterium absorption in high-redshift,…
We explore the effect of neutron lifetime and its uncertainty on standard big-bang nucleosynthesis (BBN). BBN describes the cosmic production of the light nuclides $^1{\rm H}$, ${\rm D}$, $^3{\rm H}$+$^3{\rm He}$, $^4{\rm He}$, and $^7{\rm…
Big Bang Nucleosynthesis can provide, via constraints on the expansion rate at that time, limits on possible variations in Newton's Constant, $G$. The original analyses were performed before an independent measurement of the…
Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) anisotropies independently predict the universal baryon density. Comparing their predictions will provide a fundamental test on cosmology. Using BBN and the CMB…
We present cosmological constraints on deviations of Newton's constant at large scales, analyzing latest cosmic microwave background (CMB) anisotropies and primordial abundances of light elements synthesized by big bang nucleosynthesis…
We examine Big Bang nucleosynthesis (BBN) in the case of inhomogenous neutrino degeneracy, in the limit where the fluctuations are sufficiently small on large length scales that the present-day element abundances are homogeneous. We…
Primordial or big bang nucleosynthesis (BBN) is one of the three historical strong evidences for the big bang model. The recent results by the Planck satellite mission have slightly changed the estimate of the baryonic density compared to…