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It has recently been shown that the observed Hubble function for cosmological expansion can be fitted accurately back to redshift unity (7.33 Gyr ago) with only one free constant, while neglecting cosmic curvature and mass, using the…

General Physics · Physics 2021-05-26 R. K. Nesbet

Holographic cosmology offers a novel framework for describing the very early Universe in which cosmological predictions are expressed in terms of the observables of a three dimensional quantum field theory (QFT). This framework includes…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-14 Niayesh Afshordi , Elizabeth Gould , Kostas Skenderis

In this paper, we use a newly compiled sample of ultra-compact structure in radio quasars and strong gravitational lensing systems with quasars acting as background sources to constrain six spatially flat and non-flat cosmological models…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-07 Tonghua Liu , Shuo Cao , Xiaolei Li , Hao Zheng , Yuting Liu , Wuzheng Guo , Chenfa Zheng

Even though the Dark Energy Spectroscopic Instrument (DESI) mission does not exclude a dynamical dark energy evolution, the concordance paradigm, i.e., the $\Lambda$CDM model, remains statistically favored, as it depends on the fewest…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-08 Anna Chiara Alfano , Orlando Luongo , Marco Muccino

We investigate the viability of a cosmological scenario with interacting dark sector, which can describe the coexistence between dark energy and dark matter. The model possesses an analytical solution for the Hubble function and we…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Shambel Sahlu , Andronikos Paliathanasis , Genly Leon , Amare Abebe

Holographic dark energy cosmology, also known as entropic cosmology, provides a concrete physical understanding of the late accelerated expansion of the universe. The acceleration appears to be a consequence of entropy associated with…

General Relativity and Quantum Cosmology · Physics 2024-06-03 Facundo Abaca , Dario Javier Zamora

A galaxy's morphological features encode details about its gas content, star formation history, and feedback processes, which play important roles in regulating its growth and evolution. We use deep convolutional neural networks (CNNs) to…

Astrophysics of Galaxies · Physics 2020-09-15 John F. Wu

We present results from a numerical code implementing a new method to solve the master equations describing the evolution of linear perturbations in a spherically symmetric but inhomogeneous background. This method can be used to simulate…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-20 Sean February , Julien Larena , Chris Clarkson , Denis Pollney

In the context of f(R,T) theories of gravity, we study the evolution of scalar cosmological perturbations in the metric formalism. According to restrictions on the background evolution, a specific model within these theories is assumed in…

General Relativity and Quantum Cosmology · Physics 2013-06-20 F. G. Alvarenga , A. de la Cruz-Dombriz , M. J. S. Houndjo , M. E. Rodrigues , D. Sáez-Gómez

We revisit the cosmology of Covariant Galileon gravity in view of the most recent cosmological data sets, including weak lensing. As a higher derivative theory, Covariant Galileon models do not have a $\Lambda$CDM limit and predict a very…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-23 Simone Peirone , Noemi Frusciante , Bin Hu , Marco Raveri , Alessandra Silvestri

We show that various scalar field models of dark energy predict degenerate luminosity distance history of the Universe and thus cannot be distinguished by supernovae measurements alone. In particular, models with a vanishing cosmological…

High Energy Physics - Phenomenology · Physics 2009-11-07 Irit Maor , Ram Brustein

We compare a large suite of theoretical cosmological models to observational data from the cosmic microwave background, baryon acoustic oscillation measurements of expansion, Type Ia SNe measurements of expansion, redshift space distortion…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-13 Zhongxu Zhai , Michael Blanton , Anže Slosar , Jeremy Tinker

We present a numerical analysis of the cosmological evolution of scalar field dark matter (SFDM) in the Boltzmann code $\texttt{CLASS}$, based on a dynamical system analysis of previous works. We show a detailed study of the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-13 L. Arturo Ureña-López , Francisco X. Linares Cedeño

Joint studies of imaging and spectroscopic samples, informed by theory and simulations, offer the potential for comprehensive tests of the cosmological model over redshifts z<1.5. Spectroscopic galaxy samples at these redshifts can be…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-15 Kyle Dawson , Andrew Hearin , Katrin Heitmann , Mustapha Ishak , Johannes Ulf Lange , Martin White , Rongpu Zhou

Is it possible that the current cosmic accelerating expansion will turn into a decelerating one? Can this transition be realized by some viable theoretical model that is consistent with the standard Big Bang cosmology? We study a class of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Tianlong Zu , Jiewen Chen , Yang Zhang

The Hubble constant $H_0$ tension has emerged as the most serious crisis in modern cosmology, potentially indicating that the $\Lambda$CDM model may not describe our universe accurately. In this paper, we establish a new,…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-26 Yang Liu , Bao Wang , Hongwei Yu , Puxun Wu

When recent observational evidence and the GR+FRW+CDM model are combined we obtain the result that the Universe is accelerating, where the acceleration is due to some not-yet-understood "dark sector". There has been a considerable number of…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-17 Jonathan A. Pearson

Within the framework of loop quantum cosmology, there exists a semi-classical regime where spacetime may be approximated in terms of a continuous manifold, but where the standard Friedmann equations of classical Einstein gravity receive…

General Relativity and Quantum Cosmology · Physics 2009-11-10 James E. Lidsey

We study the constraints which the next generation of radio telescopes could place on the nature of dark energy, dark matter and inflation by studying the gravitational lensing of high redshift 21 cm emission, and we compare with the…

Astrophysics · Physics 2009-06-23 R. Benton Metcalf , S. D. M. White

We review the evidence for recently accelerating cosmological expansion or "dark energy", either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity), without any Dark Energy constituent. If…

Astrophysics · Physics 2007-05-23 Sidney Bludman