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Related papers: A cosmological test with compact radio sources

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We investigate the statistics of the cosmic microwave background using the Kolmogorov-Smirnov test. We show that, when we correctly de-correlate the data, the partition function of the Kolmogorov stochasticity parameter is compatible with…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-01 Mona Frommert , Ruth Durrer , Jérôme Michaud

The James Webb Space Telescope (JWST), which has recently become operational, is capable of detecting objects at record-breaking redshifts, $z \gtrsim 15$. This is a crucial advance for observational cosmology, as at these redshifts the…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 Nikita Lovyagin , Alexander. Raikov , Vladimir Yershov , Yuri Lovyagin

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…

Astrophysics · Physics 2011-02-11 Abraham Loeb

We have used the Westerbork Northern Sky Survey (WENSS) to define a sample of 47 low redshift (z < 0.4) giant radio galaxies. This is the largest sample yet of such radio sources originating from a single survey. We present radio maps of…

Astrophysics · Physics 2009-11-06 A. P. Schoenmakers , A. G. de Bruyn , H. J. A. Rottgering , H. van der Laan

The use of relations between structural parameters of early type galaxies to perform the Tolman test is reconsidered. Scaling relations such as the FP or the Kormendy relation, require the transformation from angular to metric sizes, to…

Astrophysics · Physics 2009-10-30 Mariano Moles , Ana Campos , Per Kjaergaard , Giovanni Fasano , Daniela Bettoni

We use cosmography to present constraints on the kinematics of the Universe, without postulating any underlying theoretical model. To this end, we use a Monte Carlo Markov Chain analysis to perform comparisons to the supernova Ia Union 2…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

Gravitational waves (GWs) from merging compact objects encode direct information about the luminosity distance to the binary. When paired with a redshift measurement, this enables standard-siren cosmology: a Hubble diagram can be…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-26 Amanda M. Farah , Thomas A. Callister , Jose María Ezquiaga , Michael Zevin , Daniel E. Holz

The cosmological constant problem has become one of the most important ones in modern cosmology. In this paper, we try to construct a model that can avoid the cosmological constant problem and have the potential to explain the apparent…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-26 Shuxun Tian

We explore the utility of future photometric redshift imaging surveys for delineating the large-scale structure of the Universe, and assess the resulting constraints on the cosmological model. We perform two complementary types of analysis:…

Astrophysics · Physics 2009-11-10 Chris Blake , Sarah Bridle

Data from the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT), combined with the nine-year data release from the WMAP satellite, provide very precise measurements of the cosmic microwave background (CMB) angular…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Micol Benetti , Martina Gerbino , William H. Kinney , Edward W. Kolb , Massimiliano Lattanzi , Alessandro Melchiorri , Luca Pagano , Antonio Riotto

The measurement of angular diameter distance to galaxy clusters, through combined Sunyaev-Zel'dovich (SZ) effect data with X-ray emission observations, is now a well-known probe of cosmology. Using a combination of SZ data and a map of the…

Astrophysics · Physics 2009-11-07 Asantha Cooray

We describe our program to search for and study the kilo-parsec scale radio jets in a sample of high-redshift (greater than 3.4), flat spectrum quasars using new and archival VLA data. Two of these radio jets have been imaged with Chandra,…

Astrophysics · Physics 2007-05-23 C. C. Cheung , J. F. C. Wardle , N. P. Lee

Using a new radio sample, 6C* designed to find radio galaxies at z > 4 along with the complete 3CRR and 6CE sample we extend the radio galaxy K-z relation to z~4.5. The 6C* K-z data significantly improve delineation of the K-z relation for…

In the paper we check whether the contribution of $(-)(1+z)^6$ type in the Friedmann equation can be tested. We consider some astronomical tests to constrain the density parameters in such models. We describe different interpretations of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marek Szydlowski , Wlodzimierz Godlowski , Tomasz Stachowiak

The plane-mirror symmetry previously noticed in the Cosmic Microwave Background (CMB) temperature anisotropy maps of Wilkinson Microwave Anisotropy Probe is shown to possess certain anomalous properties. The degree of the randomness…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 V. G. Gurzadyan , T. Ghahramanyan , A. L. Kashin , H. G. Khachatryan , A. A. Kocharyan , H. Kuloghlian , D. Vetrugno , G. Yegorian

Of all the distance and temporal measures in cosmology, the angular-diameter distance, d_A(z), uniquely reaches a maximum value at some finite redshift z_max and then decreases to zero towards the big bang. This effect has been difficult to…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Fulvio Melia

Precision cosmology is crucial to understand the different energy components in the Universe and their evolution through cosmic time. Gravitational wave sources are standard sirens that can accurately map out distances in the Universe.…

General Relativity and Quantum Cosmology · Physics 2022-12-27 Arnab Dhani , Ssohrab Borhanian , Anuradha Gupta , Bangalore Sathyaprakash

We calculate the expected number of strongly lensed radio sources in a sample of 6500 sources observed with the Very Large Array as part of the Cosmic Lens All Sky Survey (CLASS) during the first two sessions of its observations. A…

Astrophysics · Physics 2011-05-23 Asantha R. Cooray

We discuss the algorithmic information approach to the analysis of the observational data on the Universe. Kolmogorov complexity is proposed as a descriptor of the Cosmic Microwave Background (CMB) radiation maps. An algorithm of…

Astrophysics · Physics 2017-08-23 V. G. Gurzadyan

Kinematic and spectral studies are improving our knowledge of the age distribution in compact radio sources, providing evidence that small sources are generally very young. The properties of jets in objects spanning the size range from a…

Astrophysics · Physics 2007-07-25 M. Giroletti
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