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Anthropic models can give testable predictions, which can be confirmed or falsified at a specified confidence level. This is illustrated using the successful prediction of the cosmological constant as an example. The history and the nature…

Astrophysics · Physics 2007-06-20 Alexander Vilenkin

We review a few off-the-beaten-track ideas in cosmology. They solve a variety of fundamental problems; also they are fun. We start with a description of non-singular dilaton cosmology. In these scenarios gravity is modified so that the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Robert H. Brandenberger , Joao Magueijo

In recent years, by theory and observation cosmology has advanced substantially. Parameters of the concordance or $\Lambda$CDM cosmological model are given with unprecedented precision ("precision cosmology"). On the other side, 95% of the…

General Relativity and Quantum Cosmology · Physics 2012-04-17 Hubert F. Goenner

An artificial scale of observable cosmological constant is dynamically related to its natural bare value due to an installation of relevant coherent state for the inflationary field in a finite volume of early Universe, because of…

General Relativity and Quantum Cosmology · Physics 2014-01-15 V. V. Kiselev

A new idea of the cosmological constant is proposed in this paper. Due to the horizon is limited, the quantum fluctuation of the inflaton field is not zero, a nonzero vacuum energy is remained as a residual inflationary energy of an unusual…

High Energy Physics - Phenomenology · Physics 2007-05-23 De-Hai Zhang

A refined version of a recently introduced method for analysing the dynamics of an inhomogeneous irrotational dust universe is presented. A fully non-perturbative numerical computation of the time dependence of volume in this framework…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-01 Harald Skarke

The common attribute of all Big Bang cosmologies is that they are based on the assumption that the universe is expanding. However examination of the evidence for this expansion clearly favours a static universe. The major topics considered…

General Physics · Physics 2014-07-10 David F. Crawford

Quantum cosmology has traditionally been studied at the level of symmetry-reduced minisuperspace models, analyzing the behavior of wave functions. However, in the absence of a complete full setting of quantum gravity and detailed knowledge…

General Relativity and Quantum Cosmology · Physics 2012-09-18 Martin Bojowald

The standard concordance model of the Universe is based on the cosmological constant as the driver of accelerating expansion. This concordance model is being subjected to a growing range of inter-locking observations. In addition to using…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Sahba Yahya , Marina Seikel , Chris Clarkson , Roy Maartens , Mathew Smith

There is some evidence that the Universe is presently undergoing accelerating expansion. This has restored some credit to the scenarios with a non-vanishing cosmological constant. From the point of view of a theory of fundamental…

High Energy Physics - Phenomenology · Physics 2014-11-17 Pierre Binetruy

A bouncing cosmology with an initial matter-dominated phase of contraction during which scales which are currently probed with cosmological observations exit the Hubble radius provides a mechanism alternative to inflation for producing a…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-20 Robert H. Brandenberger

A homogeneous and isotropic cosmological model with a positive cosmological constant is considered. The matter sector is given by a massless scalar field, which can be used as an internal time to deparametrize the theory. The idea is to…

General Relativity and Quantum Cosmology · Physics 2015-04-28 David Brizuela

Cosmography is a model-independent phenomenological approach to observational cosmology, relying on Taylor series expansions of physical quantities as a function of the cosmological redshift or other analogous variables. A recent work…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-27 C. J. A. P. Martins

Even when completely and consistently formulated, a fundamental theory of physics and cosmological boundary conditions may not give unambiguous and unique predictions for the universe we observe; indeed inflation, string/M theory, and…

High Energy Physics - Theory · Physics 2009-10-07 Anthony Aguirre , Max Tegmark

Astronomical observations have shown that the expansion of the universe is at present accelerating, in a way consistent with the presence of a positive cosmological constant. This is a major puzzle, because we do not understand: why the…

Astrophysics · Physics 2007-05-23 Jordi Miralda-Escude

Loop quantum cosmology is an application of recent developments for a non-perturbative and background independent quantization of gravity to a cosmological setting. Characteristic properties of the quantization such as discreteness of…

Astrophysics · Physics 2009-11-13 Martin Bojowald

Observational Cosmology has indeed made very rapid progress in recent years. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation Measurements of CMB anisotropy and, more…

Astrophysics · Physics 2009-11-11 Tarun Souradeep

There has been significant recent progress in observational cosmology. This, in turn, has provided an unprecedented picture of the early universe and its evolution. In this review I will present a (biased) view of how one can use these…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Raul Jimenez

Quantization of a dust-like closed isotropic cosmological model with a cosmological constant is realized by the method of B. DeWitt \cite{1}. It is shown that such quantization leads to interesting results, in particular, to a finite…

General Relativity and Quantum Cosmology · Physics 2009-09-25 M. I. Kalinin , V. N. Melnikov

The suggested alternative cosmology is based on the idea of barion symmetric universe, in which our home universe is a representative of multitude of typical matter and antimatter universes. This alternative concept gives a physically…

Astrophysics · Physics 2016-08-30 A. Vankov