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The exploration of the redshift drift, a direct measurement of cosmological expansion, is expected to take several decades of observation with stable, sensitive instruments. We introduced a new method to probe cosmology which bypasses the…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-16 Chengyi Wang , Krzysztof Bolejko , Geraint F. Lewis

A scale-dependent cosmology is proposed in which the Robertson-Walker metric and the Einstein equation are modified in such a way that $\Omega_0$, $H_0$ and the age of the Universe all become scale-dependent. Its implications on the…

High Energy Physics - Phenomenology · Physics 2009-10-28 C. W. Kim , T. H. Lee , J. Song

Intrigued by the holographic principle, Padmanabhan recently proposed a novel idea, saying that our cosmic space is emergent as cosmic time progresses. In particular, the expansion rate of the Universe is related to the difference between…

High Energy Physics - Theory · Physics 2013-09-12 Yi Ling , Wen-Jian Pan

In the past decade, observational cosmology has had one of the most exciting periods in the past century. The precision with which we have been able to measure cosmological parameters has increased tremendously, while at the same time, we…

Astrophysics · Physics 2009-11-07 Lawrence M. Krauss

In this paper we present a new simple method of construction of infinite number of solutions of Freidmann equations from the already known ones, which allows for a startling conclusion of practical impossibility of correct predictions on…

Astrophysics · Physics 2010-11-23 A. V. Yurov , V. A. Astashenok , V. A. Yurov

The absence of guidance from fundamental physics about the mechanism behind cosmic acceleration has given rise to a number of alternative cosmological scenarios. These are based either on modifications of general relativistic gravitation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 M. A. Dantas , J. S. Alcaniz , D. Mania , Bharat Ratra

There is a deep cosmological mystery: although dependent on very different underlying physics, the timescales of structure formation, of galaxy cooling (both radiatively and against the CMB), and of vacuum domination do not differ by many…

High Energy Physics - Theory · Physics 2009-09-24 Raphael Bousso , Lawrence J. Hall , Yasunori Nomura

In a recent paper [arXiv:1206.4916] by T. Padmanabhan, it was argued that our universe provides an ideal setup to stress the issue that cosmic space is emergent as cosmic time progresses and that the expansion of the universe is due to the…

General Relativity and Quantum Cosmology · Physics 2012-11-09 Rong-Gen Cai

Exclusion zones in the cross-correlations between critical points (peak-void, peak-wall, filament-wall, filament-void) of the density field define quasi-standard rulers that can be used to constrain dark matter and dark energy cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-19 Junsup Shim , Christophe Pichon , Dmitri Pogosyan , Stephen Appleby , Corentin Cadiou , Juhan Kim , Katarina Kraljic , Changbom Park

Subject of this contribution is to demonstrate that the observed faintness of the supernovae at the high redshift can be considered as a manifestation of quantum effects at cosmological scales. We show that observed redshift distribution of…

Astrophysics · Physics 2007-05-23 V. V. Kuzmichev

Observables such as the luminosity function of galaxies, \Phi(M), the projected clustering of galaxies, w_p(r_p), and the galaxy-galaxy lensing signal, \Delta\Sigma, are often measured from galaxy redshift surveys assuming a fiducial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Surhud More

We review the main scientific pictures of the universe developed from ancient times to Albert Einstein and underline that all of them treated the universe as a stationary system with unchanged physical properties. In contrast to this, 100…

Popular Physics · Physics 2022-12-01 Galina L. Klimchitskaya , Vladimir M. Mostepanenko

We study some aspects of cosmologies in 5D models with one infinite extra dimension. Matter is confined to the brane, gravity extends to the bulk. Models with positive and negative tension of the brane are considered. Cosmological evolution…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Mikhail Z. Iofa

The coincidence problem among the pure numbers of order near 10^{40} is resolved with the Raychaudhuri and Friedmann-Robertson-Lemaitre-Walker equations and a trivial relationship involving the fine structure constant. The fact that the…

General Physics · Physics 2009-11-11 Scott Funkhouser

The cosmological scale factor $a(t)$ of the flat-space Robertson-Walker geometry is examined from a Hamiltonian perspective wherein $a(t)$ is interpreted as an independent dynamical coordinate and the curvature density $\sqrt {- g(a)}…

General Physics · Physics 2008-10-04 M. Ibison

The dependence of luminosity distance on observed resdhift and the cosmological parameters H and q is derived for a contracting Friedmann universe with no cosmological constant. The result is consistent with recent supernovae observations.

Astrophysics · Physics 2007-05-23 W. Q. Sumner , E. E. Vityaev

Cosmology has come a long way from being based on a small number of observations to being a data-driven precision science. We discuss the questions "What is observable?", "What in the Universe is knowable?" and "What are the fundamental…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-28 Florent Leclercq , Alice Pisani , Benjamin D. Wandelt

Dynamical systems techniques are a powerful tool to analyse systems of ordinary differential equations, written in an appropriate form. For a given theory of gravity, the cosmological field equations typically lead to a system of ordinary…

General Relativity and Quantum Cosmology · Physics 2026-05-13 Christian G. Boehmer , Antonio d'Alfonso del Sordo

A moderate investment of observing time with the International X-ray Observatory to study high-redshift galaxy clusters detected in future large-scale surveys, will provide cosmological measurements of fundamental importance. IXO…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-16 A. Vikhlinin , S. W. Allen , M. Arnaud , M. Bautz , H. Boehringer , M. Bonamente , J. Burns , A. Evrard , J. P. Henry , C. Jones , B. R. McNamara , D. Nagai , D. Rapetti , T. Reiprich

A general formula for the correlation function in redshift space is derived in linear theory. The formula simultaneously includes wide-angle effects and cosmological distortions. The formula is applicable to any pair with arbitrary angle…

Astrophysics · Physics 2009-10-31 Takahiko Matsubara