Related papers: Tracing dark energy with quasars
Quasars, as the most luminous persistent sources in the Universe, have broad applications for cosmological studies. In particular, they can be employed to directly measure the expansion history of the Universe, similarly to SNe Ia. The…
Discoveries in the last few years have revolutionized our knowledge of the universe and our ideas of its ultimate fate. Measurements of the expansion of the universe show that it is not slowing down under normal gravity but accelerating due…
Exploring the recent expansion history of the universe promises insights into the cosmological model, the nature of dark energy, and potentially clues to high energy physics theories and gravitation. We examine the extent to which precision…
In the near future, new surveys promise a significant increase in the number of quasars (QSO) at large redshifts. This will help to constrain the dark energy models using quasars. The Large Synoptic Survey Telescope (LSST) will cover over…
High redshift quasars can be used to deduce the distribution of dark energy in the Universe, as a complementary tool to SN Ia. The method is based on determination of the size of the Broad Line Region from the emission line delay,…
The nature of dark energy remains a profound mystery 20 years after the discovery of cosmic acceleration. A very high number density galaxy redshift survey over a wide area (HD GRS Wide) spanning the redshift range of 0.5<z<4 using the same…
The variation of the expansion rate of the Universe with time produces an evolution in the cosmological redshift of distant sources (for example quasar Lyman-$\alpha$ absorption lines), that might be directly observed by future ultra…
Strong lensing gravitational time delays are a powerful and cost effective probe of dark energy. Recent studies have shown that a single lens can provide a distance measurement with 6-7 % accuracy (including random and systematic…
A huge amount of good quality data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision Cosmology. Despite…
Galaxy redshift surveys using optical telescopes have, in combination with other cosmological probes, enabled precision measurements of the nature of dark energy. We show that radio telescopes are rapidly becoming competitive with optical…
The explanation of the accelerated expansion of the Universe poses one of the most fundamental questions in physics and cosmology today. If the acceleration is driven by some form of dark energy, one can try to constrain the parameters…
Reverberation mapping technique is an important milestone in AGN demographics, kinematics and the structure of the Broad Line Region (BLR) based on the time-delay response between the continuum and emission line. The time delay is directly…
This talk presents a pedagogical discussion of how precision distance-redshift observations can map out the recent expansion history of the universe, including the present acceleration and the transition to matter dominated deceleration.…
The acceleration of the expansion of the universe has deep implications for structure formation, the composition of the universe, and its fate. Roughly 70% of the energy density is in a dark energy, whose nature remains unknown. Mapping the…
It has now been firmly established that the Universe is expanding at an accelerated rate, driven by a presently unknown form of dark energy that appears to dominate our Universe today. A dedicated satellite mission has been designed to…
Breakthroughs in physics and astrophysics are often driven by technological advances, with the recent detection of gravitational waves being one such example. This white paper focuses upon how improved astrometric and spectroscopic…
The discovery of dark energy by the first generation of high-redshift supernova surveys has generated enormous interest beyond cosmology and has dramatic implications for fundamental physics. Distance measurements using supernova explosions…
Astrophysical observations are pointing out huge amounts of dark matter and dark energy needed to explain the observed large scale structures and cosmic accelerating expansion. Up to now, no experimental evidence has been found, at…
Observational evidence for the accelerated expansion of the universe requires dark energy for its explanation if general relativity is an accurate model of gravity. However, dark energy is a mysterious quantity and we do not know much about…
In the near future, the arrival of new surveys promises a significant increment in the number of quasars (QSO) at large redshift ranges. This will help to constrain the dark energy models using quasars. The Large Synoptic Survey Telescope…