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Related papers: Do anthropic arguments really work?

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We discuss models in which the smallness of the effective vacuum energy density $\rho_\L$ and the coincidence of the time of its dominance $t_\L$ with the epoch of galaxy formation $t_G$ are due to anthropic selection effects. In such…

Astrophysics · Physics 2009-10-31 Jaume Garriga , Alexander Vilenkin

We discuss the Carter's formula about the mankind evolution probability following the derivation proposed by Barrow and Tipler. We stress the relation between the existence of billions of galaxies and the evolution of at least one…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. Feoli , S. Rampone

This paper focuses on two aspects of the statistics of cosmological observables that are important for the next stages of precision cosmology. First, we note that the theory of reduced angular $N$-point spectra has only been developed in…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-02 Ermis Mitsou , Jaiyul Yoo , Ruth Durrer , Fulvio Scaccabarozzi , Vittorio Tansella

The original formulation of the (weak) anthropic principle was prompted by a question about objective time at a macroscopic level, namely the age of the universe when ``anthropic'' observers such as ourselves would be most likely to emerge.…

High Energy Physics - Theory · Physics 2007-10-23 Brandon Carter

We use the existence of habitable planets to impose anthropic requirements on the fine structure constant, $\alpha$. To this effect, we present two considerations that restrict its value to be very near the one observed. The first, that the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-18 McCullen Sandora

We undertake a critical evaluation of recent observational information on $\Omega_m$ and $\Omega_\Lambda$ in order to identify possible sources of systematic errors and effects of simplified statistical analyses. We combine observations for…

Astrophysics · Physics 2009-11-06 S. M. Harun-or-Rashid , M. Roos

Independent tests aiming to constrain the value of the cosmological constant $\Lambda$ are usually difficult because of its extreme smallness $\left(\Lambda \simeq 1\times 10^{-52}~\textrm{m}^{-2},~\textrm{or}~2.89\times…

General Relativity and Quantum Cosmology · Physics 2018-03-28 Lorenzo Iorio

We reanalyse optical gravitational lens surveys from the literature in order to determine relative probabilities in the $\lambda_{0}$-$\Omega_{0}$ plane, using a softened singular isothermal sphere lens model. In addition, we examine a…

Astrophysics · Physics 2007-05-23 Ralf Quast , Phillip Helbig

The presence of a cosmological constant, Lambda, in an action with higher powers of the curvature can produce rapidly oscillating metrics. We develop a perturbative approach for generating periodic solutions to the non-linear field…

High Energy Physics - Theory · Physics 2009-11-07 Hael Collins , Bob Holdom

In this paper we provide both a diagnosis and resolution of the cosmological constant problem, one in which a large (as opposed to a small) cosmological constant $\Lambda$ can be made compatible with observation. We trace the origin of the…

Astrophysics · Physics 2009-10-31 Philip D. Mannheim

Current cosmological observations indicate a preference for a cosmological constant that is drastically smaller than what can be explained by conventional particle physics. The Causal Entropic Principle (Bousso, {\it et al}.) provides an…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-08 Brandon Bozek , Andreas Albrecht , Daniel Phillips

We present a possible understanding to the issues of cosmological constant, inflation, matter and coincidence problems based only on the Einstein equation and Hawking particle production. The inflation appears and results agree to…

General Physics · Physics 2020-06-26 She-Sheng Xue

It has been shown that the new Self Creation Cosmology theory predicts a universe with a total density parameter of one third yet spatially flat, which would appear to accelerate in its expansion. Although requiring a moderate amount of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Garth A Barber

In the context of open inflation, we calculate the probability distribution for the density parameter $\Omega$. A large class of two field models of open inflation do not lead to infinite open universes, but to an ensemble of inflating…

Astrophysics · Physics 2009-10-30 Jaume Garriga , Takahiro Tanaka , Alexander Vilenkin

In this work a satisfactory, simple theoretical prediction of the data corresponding to observationally (by fine tuning condition) estimated value of the cosmological constant is given. It is supposed (in conceptually analogy with…

Astrophysics · Physics 2007-12-27 Vladan Pankovic , Simo Ciganovic , Jovan Ivanovic , Rade Glavatovic , Petar Grujic

The Cosmic Defect theory has been confronted with four observational constraints: primordial nuclear species abundances emerging from the big bang nucleosynthesis; large scale structure formation in the universe; cosmic microwave background…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 N. Radicella , M. Sereno , A. Tartaglia

I will review some results of observational cosmology which critically cast doubt upon the foundations of the standard cosmology: 1) The redshifts of the galaxies are due to the expansion of the Universe; 2) The cosmic microwave background…

Astrophysics · Physics 2007-05-23 Martin Lopez-Corredoira

We derive new limits on the value of the cosmological constant, $\Lambda$, based on the Einstein bending of light by systems where the lens is a distant galaxy or a cluster of galaxies. We use an amended lens equation in which the…

Astrophysics · Physics 2009-11-13 Mustapha Ishak , Wolfgang Rindler , Jason Dossett , Jacob Moldenhauer , Chris Allison

Recent observations of high-redshift supernovae seem to suggest that the global geometry of the Universe may be affected by a `cosmological constant', which acts to accelerate the expansion rate with time. But these data by themselves still…

Astrophysics · Physics 2009-10-31 Idit Zehavi , Avishai Dekel

The binding energy parameter $\lambda$ plays a vital role in common envelope evolution. Though it is well known that $\lambda$ takes different values for stars with different masses and varies during stellar evolution, it has been…

Solar and Stellar Astrophysics · Physics 2016-08-17 Cheng Wang , Kun Jia , Xiang-Dong Li
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