99 citations · 250 across the 7 of their papers we have counts for
7 papers
Determination of HII region metallicity in the context of estimating the primordial helium abundance
O. A. Kurichin, P. A. Kislitsyn, A. V. Ivanchik
The primordial He abundance (Y) is one of the key characteristics of Primordial Nucleosynthesis processes that occurred in the first minutes after the Big Bang. Its value d…
Absorption of Photons from Distant Gamma-Ray Sources
A. N. Popov, D. P. Barsukov, A. V. Ivanchik
Being the largest gravitationally bound structures in the Universe, galaxy clusters are huge reservoirs of photons generated by the bremsstrahlung of a hot cluster gas. We consider…
Variation of the baryon-to-photon ratio due to decay of dark matter particles
E. O. Zavarygin, A. V. Ivanchik
The influence of dark matter particle decay on the baryon-to-photon ratio has been studied for different cosmological epochs. We consider different parameter values of dark matter…
Constraining fundamental constants of physics with quasar absorption line systems
Patrick Petitjean, Raghunathan Srianand, Hum Chand +3
We summarize the attempts by our group and others to derive constraints on variations of fundamental constants over cosmic time using quasar absorption lines. Most upper limits res…
HD molecules at high redshift: A low astration factor of deuterium in a solar-metallicity DLA system at z=2.418
P. Noterdaeme, P. Petitjean, C. Ledoux +2
We present the detection of deuterated molecular hydrogen (HD) in the remote Universe in a damped Lyman-alpha cloud at zabs=2.418 toward the quasar SDSS J143912.04+111740.5. This i…
A new constraint on the time dependence of the proton-to-electron mass ratio. Analysis of the Q 0347-383 and Q 0405-443 spectra
A. Ivanchik, P. Petitjean, D. Varshalovich +5
A new limit on the possible cosmological variation of the proton-to-electron mass ratio μ=m_p/m_e is estimated by measuring wavelengths of H_2 lines of Lyman and Werner bands from…