Related papers: Minimal Angular Size of Distant Sources in Open, $…
Hubble Space Telescope images of high-redshift galaxies selected via color and photometric redshifts are used to examine the size and axial-ratio distribution of galaxies as a function of redshift at lookback times t > 8 Gyr. These…
In this paper, based on a 2.29 GHz VLBI all-sky survey of 613 milliarcsecond ultra-compact radio sources with $0.0035<z<3.787$, we describe a method of identifying the sub-sample which can serve as individual standard rulers in cosmology.…
We constrain the parameters describing the kinematical state of the universe using a cosmographic approach, which is fundamental in that it requires a very minimal set of assumptions (namely to specify a metric) and does not rely on the…
The rotational velocity of distant galaxies, when interpreted as a size (luminosity) indicator, may be used as a tool to select high redshift standard rods (candles) and probe world models and galaxy evolution via the classical angular…
The Little Red Dots (LRDs) are high-redshift galaxies uncovered by JWST, characterized by small effective radii ($R_{\rm eff} \sim 80-300$ pc), number densities that are intermediate between those of typical galaxies and quasars, and a…
Measurements of the Hubble constant, and more generally measurements of the expansion rate and distances over the interval $0 < z < 1$, appear to be inconsistent with the predictions of the standard cosmological model ($\Lambda$CDM) given…
We place tight constraints on the main cosmological parameters of spatially flat cosmological models by using the recent angular clustering results of XMM-{\it Newton} soft (0.5-2 keV) X-ray sources (Ebrero et al. 2009a), which have a…
We search for magnetic fields outside galaxies and galaxy clusters by investigating redshift evolution of Faraday rotation measures (RM) of extragalactic radio sources. Our analysis reveals a strong evidence for the redshift dependence of…
Current and upcoming wide-field surveys for weak gravitational lensing and the Sunyaev-Zel'dovich effect will generate mass-selected catalogues of dark matter halos with internal or followup photometric redshift information. The angular…
We have re-examined an ancient VLBI survey of ultra-comact radio sources at 2.29 GHz, which gave fringe amplitudes for 917 such objects with total flux density >0.5 Jy approximately. A number of cosmological investigations based upon this…
Faraday rotation studies of distant radio sources can constrain the evolution and the origin of cosmic magnetism. We use data from the LOFAR Two Metre Sky Survey: Data Release 2 (LoTSS DR2) to study the dependence of the Faraday rotation…
The influence of dark matter inhomogeneities on the angular size-redshift test is investigated for a large class of flat cosmological models driven by dark energy plus a cold dark matter component (XCDM model). The results are presented in…
Under the assumption that the gas mass fraction of galaxy clusters estimated out to an outer hydrostatic radius is constant, it is possible to constrain the cosmological parameters by using the angular diameter distance relation with…
We investigate the cosmological test recently proposed by B. Fort, Y. Mellier and M. Dantel-Fort (FMD), where the observed location of the critical line in gravitational lensing is used to determine the cosmological parameters, $\Omega$ and…
The dispersion measure (DM) of fast radio bursts (FRBs) provides a unique way to probe ionised baryons in the intergalactic medium (IGM). Cosmological models with different parameters lead to different DM-redshift ($\mathrm{DM}-z$)…
The redshift of all cosmological sources drifts by a systematic velocity of order a few m/s over a century due to the deceleration of the Universe. The specific functional dependence of the predicted velocity shift on the source redshift…
We develop a cosmographic framework for analysing redshift drift signals of nearby sources model-independently, i.e., without making assumptions about the metric description of the Universe. We show that the…
We use a strong lensing inversion in the cluster of galaxies AC 114 to derive constraints on the cosmological parameters Omega_M0 and Omega_Lambda. If it is possible to measure spectroscopically the redshifts of many multiple images then…
The cosmographic approach is gaining considerable interest as a model-independent technique able to describe the late expansion of the universe. Indeed, given only the observational assumption of the cosmological principle, it allows to…
We present evidence for a positive angular correlation between bright submillimetre sources and low-redshift galaxies. The study was conducted using 39 sources selected from 3 contiguous, flux-limited SCUBA surveys, cross-correlated with…