4 papers · 1 filter
Primordial Deuterium Abundance Measurements
Sergei A. Levshakov, Wilhelm H. Kegel, Fumio Takahara
Deuterium abundances measured recently from QSO absorption-line systems lie in the range from 3 10^{-5} to 3 10^{-4}, which shed some questions on standard big bang theory. We show…
The primordial deuterium abundance : problems and prospects
Sergei A. Levshakov, Fumio Takahara, Wilhelm H. Kegel
The current status of extragalactic deuterium abundance is discussed using two examples of `low' and `high' D/H measurements. We show that the discordance of these two types of D a…
How accurately can the deuterium abundance be determined ?
S. A. Levshakov, W. H. Kegel, F. Takahara
By using a Reverse Monte Carlo technique aimed at the inverse problem in the analysis of the H+D Ly-a absorption from QSO spectra we have estimated the physical parameters of the g…
What causes the Ly-alpha forest, clouds or large-scale velocity fields ?
W. H. Kegel, S. A. Levshakov
We show that in stochastic large scale velocity fields superposed on the general Hubble flow, the formation of the GP-depression in QSO spectra is intimately related to the formati…