146 citations · 334 across the 11 of their papers we have counts for
11 papers
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 Cosmic Evolution of Magnesium Isotopes
E. Vangioni, K. A. Olive
The abundance of magnesium in the interstellar medium is a powerful probe of star formation processes over cosmological timescales. Magnesium has three stable isotopes, 24Mg, 25Mg,…
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…
Lithium abundances of halo dwarfs based on excitation temperatures. II. NLTE
A. Hosford, A. E. Garcia Perez, R. Collet +3
One of the most important factors in determining the stellar lithium abundance is the effective temperature. In a previous study by the authors, new effective temperatures Teff for…
Influence of Population III stars on cosmic chemical evolution
E. Rollinde, E. Vangioni, D. Maurin +4
New observations from the Hubble ultra deep field suggest that the star formation rate at z>7 drops off faster than previously thought. Using a newly determined star formation rate…
Frequentist Estimation of Cosmological Parameters from the MAXIMA-1 Cosmic Microwave Background Anisotropy Data
M. E. Abroe, A. Balbi, J. Borrill +12
We use a frequentist statistical approach to set confidence intervals on the values of cosmological parameters using the MAXIMA-1 and COBE measurements of the angular power spectru…
Axions and the Graceful Exit Problem in String Cosmology
N. Kaloper, R. Madden, K. A. Olive
We reexamine the graceful exit problem in the Pre-Big-Bang inflationary scenario. The dilaton-gravity action is generalized by adding the axion and a general axion/dilaton potentia…
Implications of a High Population II B/Be Ratio
B. Fields, K. Olive, D. Schramm
The observed B/Be ratio in extreme Pop II stars has been interpreted as evidence of Be and B synthesis by early galactic cosmic rays. However, a recent reanalysis of the boron abun…