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Observations of H2 spectra in the line-of-sight of distant quasars may reveal a variation of the proton-electron mass ratio mu=m_p/m_e at high redshift, typically for z>2. Currently four high-quality systems (Q0347-383, Q0405-443, Q0528-250 and J2123-005) have been analyzed returning a constraint Dmu/mu < 1 x 10^{-5}. We present data and a mu-variation analysis of another system, Q2348-011 at redshift z_{abs}=2.42, delivering dmu/mu = (-1.5 pm 1.6) x 10^{-5}. In addition to observational data the status of the laboratory measurements is reviewed. The future possibilities of deriving a competitive constraint on Dmu/mu from the known high-redshift H2 absorbers is investigated, resulting in the identification of a number of potentially useful systems for detecting mu-variation.
Molecular hydrogen (H2) absorption features observed in the line-of-sight to Q2348-011 at redshift zabs = 2.426 are analysed for the purpose of detecting a possible variation of the proton-to-electron mass ratio mu=mp/me. By its structure Q2348-011 i
We carry out a search for signatures of cosmological time dilation in the light curves of Gamma Ray Bursts (GRBs), detected by the Neil Gehrels Swift Observatory. For this purpose, we calculate two different durations ($T_{50}$ and $T_{90}$) for a sa
From a search of a ~ 2400 square degree region covered by both the SDSS and UKIDSS databases, we have attempted to identify galaxies at z ~ 0.5 that are consistent with their being essentially unmodified examples of the luminous passive compact galax
We compute the infrared (IR) emission from high-redshift galaxies in cosmological smoothed particle hydrodynamics simulations by coupling the output of the simulation with the population synthesis code `GRASIL by Silva et al. Based on the stellar mas
We performed a search for the HeH+ J=1-0 line ( u_{rest} = 2010.183873 GHz) and simultaneously for the CH ^2Pi_{3/2}(F_2)J=3/2 - ^2Pi_{1/2}(F_2)J=1/2 lines ( u_{rest}approx 2006.8 and 2010.8 GHz) toward one of the highest-redshift quasars known, SDSS