English
Related papers

Related papers: Precision Primordial $^4$He Measurement with CMB E…

200 papers

Cosmological measurements over the next decade will enable us to shed light on the content and evolution of the Universe. Complementary measurements of the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations are expected to…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-10 Siddharth Mishra-Sharma , David Alonso , Joanna Dunkley

The recent Boomerang and MAXIMA data on the cosmic microwave background suggest a large value for the baryonic matter density of the universe, omega_b = 0.03. This density is larger than allowed by standard big bang nucleosynthesis theory…

Astrophysics · Physics 2009-10-31 Hannu Kurki-Suonio , Elina Sihvola

The Cosmic Microwave Background Radiation (CMB) is an invaluable probe of the conditions of the early universe. Recent measurements of its spatial anisotropy have allowed accurate determinations of several fundamental cosmological…

Astrophysics · Physics 2009-09-29 Christopher O'Dell

Recent results from BOOMERANG-98 and MAXIMA-1, taken together with COBE-DMR, provide consistent and high signal-to-noise measurements of the CMB power spectrum at spherical harmonic multipole bands over $2<\ell\lta800$. Analysis of the…

We consider the perturbation dynamics for the cosmic baryon fluid and determine the corresponding power spectrum for a $\Lambda(t)$CDM model in which a cosmological term decays into dark matter linearly with the Hubble rate. The model is…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-30 R. F. vom Marttens , W. S. Hipólito-Ricaldi , W. Zimdahl

(Abridged) In the presence of a light WIMP (< 30 MeV), there are degeneracies among the nature of the WIMP, its couplings to standard model particles, its mass m_chi, and the number of equivalent neutrinos beyond the standard model, Delta…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-23 Kenneth M. Nollett , Gary Steigman

We derive constraints on the injection of free-streaming dark radiation after big bang nucleosynthesis (BBN) by considering the decay of a massive hidden sector particle into dark radiation. Such a scenario has the potential to alleviate…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-12 Alexander C. Sobotka , Adrienne L. Erickcek , Tristan L. Smith

Big-Bang Nucleosynthesis (BBN) predictions of primordial light-element abundances offer a powerful probe of early-Universe physics. However, high-accuracy numerical BBN calculations have become a major computational bottleneck for…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-18 Fan Zhang , Hang Diao , Bohua Li , Joel Meyers , Paul R. Shapiro

The search for primordial gravitational waves in the Cosmic Microwave Background (CMB) will soon be limited by our ability to remove the lensing contamination to $B$-mode polarization. The often-used quadratic estimator for lensing is known…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-04 Marius Millea , Ethan Anderes , Benjamin D. Wandelt

We verified the validity of the empirical method to derive the 4He abundance used in our previous papers by applying it to CLOUDY (v13.01) models. Using newly published HeI emissivities, for which we present convenient fits as well as the…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-03 Y. I. Izotov , G. Stasinska , N. G. Guseva

We derive new CMB anisotropy power spectrum and BBN constraints for evaporating primordial black holes by explicitly solving the electromagnetic particle cascades of emitted particles and the deposition of this emitted energy to the…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-14 Sandeep Kumar Acharya , Rishi Khatri

This is a reply report to astro-ph/0604264. We studied heavy element production in high baryon density region in early universe astro-ph/0507439. However it is claimed in astro-ph/0604264 that small scale but high baryon density region…

Astrophysics · Physics 2009-11-13 Shunji Matsuura , Shin-ichirou Fujimoto , Masa-aki Hashimoto , Katsuhiko Sato

We investigate Big Bang nucleosynthesis (hereafter, BBN) in a cosmic environment characterized by a distribution of small-scale matter/antimatter domains. Production of antimatter domains in a baryo-asymmetric universe is predicted in some…

Astrophysics · Physics 2009-10-30 Jan B. Rehm , Karsten Jedamzik

We compare the latest observations of Cosmic Microwave Background (CMB) Anisotropies with the theoretical predictions of the standard scenario of structure formation. Assuming a primordial power spectrum of adiabatic perturbations we found…

Astrophysics · Physics 2009-11-07 Alessandro Melchiorri , Carolina Odman

We improve Standard Big Bang Nucleosynthesis (SBBN) calculations taking into account new nuclear physics analyses (Descouvemont et al. 2003). Using a Monte-Carlo technique, we calculate the abundances of light nuclei versus the baryon to…

Astrophysics · Physics 2009-11-10 A. Coc , E. Vangioni-Flam , P. Descouvemont , A. Adahchour , C. Angulo

We discuss the present bounds on the relativistic energy density in the Universe parameterized in terms of the effective number of neutrinos N using the most recent cosmological data on Cosmic Microwave Background (CMB) temperature…

Astrophysics · Physics 2010-10-27 Gianpiero Mangano , Alessandro Melchiorri , Olga Mena , Gennaro Miele , Anze Slosar

We discuss how measurements of fluctuations in the absorption of cosmic microwave background (CMB) photons by neutral gas during the cosmic dark ages, at redshifts z ~ 7--200, could reveal the primordial deuterium abundance of the Universe.…

Astrophysics · Physics 2007-05-23 Kris Sigurdson , Steven R. Furlanetto

We test different Big Bang Nucleosynthesis scenarios using the recent results on the Cosmic Microwave Background Anisotropies provided by the BOOMERanG and MAXIMA-1 experiments versus the observed abundances of 4He, D and 7Li. The…

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

We calculate and display the primordial light-element abundances as a function of a neutrino degeneracy parameter \xi common to all flavors. It is the only unknown parameter characterizing the thermal medium at the primordial…

Astrophysics · Physics 2009-11-11 Pasquale D. Serpico , Georg G. Raffelt

We summarize some applications of big bang nucleosythesis (BBN) and the cosmic microwave background (CMB) to constrain the first moments of the creation of matter in the universe. We review the basic elements of BBN and how it constraints…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Grant. J. Mathews , Mayukh Gangopadhyay , Nishanth Sasankan , Kiyotomo Ichiki , Toshitaka Kajino