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Related papers: Expanding space, quasars and St. Augustine's firew…

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The space expansion physics contains several paradoxes which were clearly demonstrated by Edward Harrison (1981, 1995, 2000), who emphasized that the cooling of homogeneous hot gas (including photon gas of CBR) in the standard cosmological…

General Relativity and Quantum Cosmology · Physics 2008-10-02 Yu. V. Baryshev

The brightnesses of supernovae are commonly understood to indicate that cosmological expansion is accelerating due to dark energy. However the entire discussion presumes a perfectly transparent universe because no effects of reddening…

Astrophysics · Physics 2015-06-24 Rudolph E. Schild , Marius Dekker

A fundamental property of an expanding universe is that any time dependent characteristic of distant objects must appear to scale by the factor $(1+z$). This is called time dilation. Light curves of type Ia supernovae and the duration of…

High Energy Astrophysical Phenomena · Physics 2019-03-06 David F. Crawford

Despite impressive phenomenological successes, cosmological models are incomplete without an understanding of what happened at the big bang singularity. Maxwell electrodynamics, considered as a source of the classical Einstein field…

General Relativity and Quantum Cosmology · Physics 2017-02-17 A. Övgün

We consider scalar perturbations of energy--density for a class of cosmological models where an early phase of accelerated expansion evolves, without any fine--tuning for graceful exit, towards the standard Friedman eras of observed…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Capozziello , G. Lambiase , G. Scarpetta

Recent studies of Type Ia Supernovae with redshifts up to about $z~\laq~1$ reveal evidence for a cosmic acceleration in the expansion of the Universe. The most straightforward explanation to account for this acceleration is a cosmological…

General Relativity and Quantum Cosmology · Physics 2009-10-31 O. Bertolami , P. J. Martins

The standard big bang cosmology has been greatly successful in explaining many observational aspects of the real universe. However, two particular diffficulties faced by it are the so-called ``horizon'' and ``flatness'' problems. By…

General Physics · Physics 2007-05-23 Abhas Mitra

The timescale of quasar variability is widely expected to show the effects of time dilation. In this paper we analyse the Fourier power spectra of a large sample of quasar light curves to look for such an effect. We find that the timescale…

Astrophysics · Physics 2009-11-06 M. R. S. Hawkins

It is shown that an exactly static and spherically symmetric black hole event horizon cannot be embedded in a time-dependent geometry. Forcing it to do so results in a naked null singularity at the would-be horizon. Therefore, since the…

General Relativity and Quantum Cosmology · Physics 2024-09-25 Valerio Faraoni , Massimiliano Rinaldi

Observations of the cosmic microwave sky are revealing the primordial non-uniformities from which all structure in the Universe grew. The only known physical mechanism for generating the inhomogeneities we see involves the amplification of…

Astrophysics · Physics 2009-10-31 Neil Turok

Over the past three years we have determined the basic features of our Universe. It is spatially flat; accelerating; comprised of 1/3 a new form of matter, 2/3 a new form of energy, with some ordinary matter and a dash of massive neutrinos;…

Astrophysics · Physics 2008-11-26 Michael S. Turner

Quantum gravity phenomenology suggests the interesting possibility that black holes are not eternal. Collapse could be halted by some unknown mechanism, or Hawking radiation might leave behind a regular spacetime. Here we investigate a…

General Relativity and Quantum Cosmology · Physics 2023-08-09 Vitor Cardoso , João L. Costa , José Natário , Zhen Zhong

One of the unresolved questions currently in cosmology is that of the non-linear accelerated expansion of the universe. This has been attributed to the so called Dark Energy (DE). The accelerated expansion of the universe is deduced from…

General Physics · Physics 2017-08-31 Kenath Arun , S B Gudennavar , A Prasad , C Sivaram

In this paper we set out to measure time dilation in quasar light curves. In order to detect the effects of time dilation, sets of light curves from two monitoring programmes are used to construct Fourier power spectra covering timescales…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-13 M. R. S. Hawkins

We examine the dynamical behavior of matter coupled to gravity in the context of a linear Klein-Gordon equation coupled to a Friedman-Robertson-Walker metric. The resulting ordinary differential equations can be decoupled, the effect of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. Christodoulakis , C. Helias , P. G. Kevrekidis , I. G. Kevrekidis , G. O. Papadopoulos

It has been demonstrated that a modern stage of the Universe expansion may be described in accordance with the observations within the scope of the space-time conformal geometry. The clock synchronization procedure in SR has been…

General Relativity and Quantum Cosmology · Physics 2010-01-21 L. M. Tomilchik , N. G. Kembrovskaya

The universe has evolved to be a filamentary web of galaxies and large inter-galactic zones of space without matter. The Euclidian nature of the universe indicates that it is not a 3D manifold within space with an extra spatial dimension.…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-29 Shlomo Barak , Elia M. Leibowitz

Intensive monitoring campaigns have recently attempted to measure the time delays between multiple images of gravitational lenses. Some of the resulting light-curves show puzzling low-level, rapid variability which is unique to individual…

Astrophysics · Physics 2015-06-24 Stuart Wyithe , Abraham Loeb

Robertson-Walker spacetimes within a large class are geometrically extended to larger cosmologies that include spacetime points with zero and negative cosmological times. In the extended cosmologies, the big bang is lightlike, and though…

Mathematical Physics · Physics 2018-01-23 David Klein , Jake Reschke

A model of the universe as a very large white hole provides a useful alternative inhomogeneous theory to pit against the homogeneous standard FLRW big bang models. The white hole would have to be sufficiently large that we can fit…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Philip Gibbs
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