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Related papers: Why anthropic reasoning cannot predict Lambda

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In calculations of the probability distribution for the cosmological constant, it has been previously assumed that the a priori probability distribution is essentially constant in the very narrow range that is anthropically allowed. This…

Astrophysics · Physics 2009-10-31 Steven Weinberg

Next year we will celebrate 100 years of the cosmological term, $\Lambda$, in Einstein's gravitational field equations, also 50 years since the cosmological constant problem was first formulated by Zeldovich, and almost about two decades of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Joan Sola

We make the cosmological constant, {\Lambda}, into a field and restrict the variations of the action with respect to it by causality. This creates an additional Einstein constraint equation. It restricts the solutions of the standard…

General Relativity and Quantum Cosmology · Physics 2015-05-28 John D. Barrow , Douglas J. Shaw

In theories in which the cosmological constant Lambda takes a variety of values in different ``subuniverses,'' the probability distribution of its observed values is conditioned by the requirement that there must be someone to measure it.…

Astrophysics · Physics 2009-10-30 Hugo Martel , Paul R. Shapiro , Steven Weinberg

The present discussion contribution is some remarks concerning and review of the proposal by one of us (C. Balazs) to explain the cosmological constant by a/the principle of entropy. Used without further comment this principle of entropy…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-26 H. B. Nielsen , C. Balazs

Many cosmologists (myself included) have advocated volume weighting for the cosmological measure problem, weighting spatial hypersurfaces by their volume. However, this often leads to the Boltzmann brain problem, that almost all…

High Energy Physics - Theory · Physics 2009-03-27 Don N. Page

Supernovae observations strongly support the presence of a cosmological constant, but its value, which we will call apparent, is normally determined assuming that the universe can be accurately described by a homogeneous model. Even in the…

General Relativity and Quantum Cosmology · Physics 2012-11-07 Antonio Enea Romano , Pisin chen

The matter content of the Universe is strongly inhomogeneous on small scales. Motivated by this fact, we consider a model of the Universe that has regularly spaced discrete masses, rather than a continuous fluid. The optical properties of…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Timothy Clifton , Pedro G. Ferreira

Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and…

High Energy Physics - Theory · Physics 2013-05-29 Grant Larsen , Yasunori Nomura , H. L. L. Roberts

Many probability measures in the multiverse depend exponentially on some observable parameters, giving rise to potential problems such as youngness bias, Q-catastrophe etc. In this paper we explore a possibility that the exponential runaway…

High Energy Physics - Theory · Physics 2010-11-03 Andrei Linde , Vitaly Vanchurin

The Doomsday argument and anthropic reasoning are two puzzling examples of probabilistic confirmation. In both cases, a lack of knowledge apparently yields surprising conclusions. Since they are formulated within a Bayesian framework, they…

Data Analysis, Statistics and Probability · Physics 2023-06-22 Yann Benétreau-Dupin

Anthropic reasoning is a form of statistical reasoning based upon finding oneself a member of a particular reference class of conscious beings. By considering empirical distribution functions defined over animal life on Earth, we can deduce…

Data Analysis, Statistics and Probability · Physics 2013-02-14 Russell K. Standish

Recently the multitude of vacua in string theory have led some authors to advocate the anthropic principle as a possible resolution for the contrived set of parameters that seem to govern our universe. I suggest that string theories should…

High Energy Physics - Theory · Physics 2007-05-23 Alon E. Faraggi

``Constants of Nature'' and cosmological parameters may in fact be variables related to some slowly-varying fields. In models of eternal inflation, such fields will take different values in different parts of the universe. Here I show how…

High Energy Physics - Theory · Physics 2009-10-31 Alexander Vilenkin

The cosmological constant, i.e., the energy density stored in the true vacuum state of all existing fields in the Universe, is the simplest and the most natural possibility to describe the current cosmic acceleration. However, despite its…

Astrophysics · Physics 2008-11-26 S. Carneiro , M. A. Dantas , C. Pigozzo , J. S. Alcaniz

We attempt to dissolve the measurement problem using an anthropic principle which allows us to invoke rational observers. We argue that the key feature of such observers is that they are rational (we need not care whether they are…

Quantum Physics · Physics 2007-05-23 Thomas Marlow

We revisit our 2013 claim [arXiv:1303.7476] that the Universe is the result of a conspiratorial plot, and find that it cannot be trusted, because even the belief in this conspiracy likely results from a conspiracy. On the basis of…

Popular Physics · Physics 2020-04-23 Jörg P. Rachen , Ute G. Gahlings

Strong gravitational lensing has traditionally been one of the few phenomena said to oppose a large cosmological constant; many analyses of lens statistics have given upper limits on $\Omega_\Lambda$ that are marginally inconsistent with…

Astrophysics · Physics 2009-11-07 Charles R. Keeton

It is well known that anthropic selection from a landscape with a flat prior distribution of cosmological constant Lambda gives a reasonable fit to observation. However, a realistic model of the multiverse has a physical volume that…

High Energy Physics - Theory · Physics 2009-02-23 Andrea De Simone , Alan H. Guth , Michael P. Salem , Alexander Vilenkin

If the parameters defining the physics of our universe departed from their present values, the observed rich structure and complexity would not be supported. This article considers whether similar fine-tuning of parameters applies to…

Popular Physics · Physics 2020-08-26 Jeffrey M. Shainline
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