7 papers
Transformation-Induced Nonthermal Neutrino Spectra and Primordial Nucleosynthesis
Kevork Abazajian, Xiangdong Shi, George M. Fuller
We examine in detail the changes in the production of primordial helium resulting from nonthermal neutrino momentum distributions produced by resonant transformation of electron-ty…
Comments Regarding "On Neutrino-Mixing-Generated Lepton Asymmetry and the Primordial Helium-4 Abundance"
Xiangdong Shi, George M. Fuller, Kevork Abazajian
This is a reply to the preprint "On Neutrino-Mixing-Generated Lepton Asymmetry and the Primordial Helium-4 Abundance" by M. V. Chizhov and D. P. Kirilova (hep-ph/9908525), which cr…
Active-Sterile Neutrino Mixing in the Early Universe and Primordial Nucleosynthesis
Kevork Abazajian, Xiangdong Shi, George M. Fuller
We investigate the effects of matter-enhanced (MSW) transformation of neutrinos in the Early Universe on the primordial helium yield (Y_p). We find that Y_p is affected much more b…
A Possible Explanation for the Radio ``Flare'' in the Early Afterglow of GRB990123
Xiangdong Shi, Geza Gyuk
We suggest that the deceleration of the relativistic shock by a denser part of the interstellar medium off line-of-sight produced the observed radio ``flare'' in the early afterglo…
A Reply to "Comment on 'Big Bang Nucleosynthesis and Active-Sterile Neutrino Mixing: Evidence for Maximal Mixing in Super Kamiokande?'"
Xiangdong Shi, George M. Fuller
In the paper "Big Bang Nucleosynthesis and Active-Sterile Neutrino Mixing: Evidence for Maximal Muon-Neutrino/Sterile-Neutrino Mixing in Super Kamiokande" (astro-ph/9810075), we su…
Are Gamma-Ray Bursts Signals of Supermassive Black Hole Formation?
Kevork Abazajian, George M. Fuller, Xiangdong Shi
The formation of supermassive black holes through the gravitational collapse of supermassive objects ($M \ga 10^4 M_\odot$) has been proposed as a source of cosmological gamma-ray…