Related papers: Giving Cosmic Redshift Drift a Whirl
From the first observations made by Slipher, our understanding and interpretation of the cosmological redshift was evolving until reaching the current consensus, through the expanding universe and the emergence of modern physical cosmology…
We revisit the epoch of cosmic speed-up characterized by the redshift of transition from a decelerated to an accelerated phase. This redshift is termed the transition redshift ($z_t$). We use the spatially Flat and Non-Flat variants of the…
In the next few years, the 21cm line will enable direct observations of the Dark Ages, Cosmic Dawn, and Reionization, which represent previously unexplored periods in our cosmic history. With a combination of sky-averaged global signal…
Assuming the existence of standard rulers, standard candles and standard clocks, requiring only the cosmological principle, a metric theory of gravity, a smooth expansion history, and using state-of-the-art observations, we determine the…
Gravitational lensing directly measures mass density fluctuations along the lines of sight to very distant objects. No assumptions need to be made concerning bias, the ratio of fluctuations in galaxy density to mass density. Hence, lensing…
Recent observational evidence in extra galactic astronomy, the interpretation of the nature of quasar redshift continues to be research interest. Spectrum observation of high redshift quasar is young in nature. Observational evidence…
In this short contribution we consider what types of surveys might be optimally pursued with path-finding instruments of 1%, 10% and finally 100% of the projected SKA sensitivity from the perspective of scientific applications that utilize…
In recent years, millisecond duration radio signals originating from distant galaxies appear to have been discovered in the so-called Fast Radio Bursts. These signals are dispersed according to a precise physical law and this dispersion is…
We study the prospects for constraining dark energy at very high redshift with the Sandage-Loeb (SL) test - a measurement of the evolution of cosmic redshift obtained by taking quasar spectra at sufficiently separated epochs. This test is…
Aims: We measure the redshift of the lensing galaxy in eight gravitationally lensed quasars in view of determining the Hubble parameter H_0 from the time delay method. Methods: Deep VLT/FORS1 spectra of lensed quasars are spatially…
The three-dimensional distribution of astronomical objects observed in redshift space significantly differs from the true distribution since the distance to each object cannot be determined by its redshift $z$ only; for $z \ll 1$ the…
Recent advancements have shown tensions between observations and our current understanding of the Universe. Such observations may include the $H_o$ tension and massive galaxies at high redshifts that are older than what traditional galaxy…
Advances in optical astrometry allow us to infer the non-radial kinematic structure of the Universe directly from observations. Here I use a supervised machine learning neural network method to predict 1.57 million redshifts based on…
To achieve the sensitivity required to detect signals from neutral hydrogen from the Cosmic Dawn and Epoch of Reionisation it is critical to have a well-calibrated instrument which has a stable calibration over the course of the…
We present measurements of both scale- and time-dependent deviations from the standard gravitational field equations. These late-time modifications are introduced separately for relativistic and non-relativistic particles, by way of the…
Many of the cosmological tests to be performed by planned dark energy experiments will require extremely well-characterized photometric redshift measurements. Current estimates are that the true mean redshift of the objects in each photo-z…
We measure photometric redshifts and spectral types for galaxies in the COSMOS survey. We use template fitting technique combined with luminosity function priors and with the option to simultaneously estimate dust extinction (i.e. E(B-V))…
Cosmic voids constitute promising cosmological laboratories. However, a full description of all the redshift-space effects that affect observational measurements is mandatory in order to obtain unbiased cosmological constraints. We make a…
High precision spectrographs can enable not only the discovery of exoplanets, but can also provide a fundamental measurement in Galactic dynamics. Over about ten year baselines, the expected change in the line-of-sight velocity due to the…
In recent years the possibility of measuring the temporal change of radial and transverse position of sources in the sky in real time have become conceivable thanks to the thoroughly improved technique applied to new astrometric and…