146 citations · 334 across the 11 of their papers we have counts for
5 papers · 1 filter
The LBT Project V: Cosmological Implications of a New Determination of Primordial He
Tsung-Han Yeh, Keith A. Olive, Brian D. Fields +5
The primordial abundance of He plays a central role in big-bang nucleosynthesis (BBN) and in the cosmic microwave background (CMB). The LBT Project's new measuremen…
The LBT Y Project IV: A New Value of the Primordial Helium Abundance
Erik Aver, Evan D. Skillman, Richard W. Pogge +7
We present a new determination of the primordial helium abundance based on new, high-quality Large Binocular Telescope (LBT) observations of 54 metal-poor H II regions. These regio…
The LBT Project I: An Improved Determination of the Primordial Helium Abundance -- Project Description, Sample Selection, Observations, and Methodology
Evan D. Skillman, Richard W. Pogge, Erik Aver +9
Extremely low metallicity HII regions have been observed with the goal of determining the primordial helium abundance (). , combined with standard big bang nu…
Limits on Non-Relativistic Matter During Big-Bang Nucleosynthesis
Tsung-Han Yeh, Keith A. Olive, Brian D. Fields
Big-bang nucleosynthesis (BBN) probes the cosmic mass-energy density at temperatures MeV to keV. Here, we consider the effect of a cosmic matter-like species t…
The primordial helium abundance from updated emissivities
Erik Aver, Keith A. Olive, R. L. Porter +1
Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y_p. The He I emissivities are the foundation of the model of the…