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Related papers: Do anthropic arguments really work?

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The definition of thermodynamic entropy is dependent on one's assignment of physical microstates to observed macrostates. As a result, low entropy in the distant past could be equivalently explained by selection of a particular observer. In…

High Energy Physics - Theory · Physics 2024-05-22 Brendon Matusch

There are now two cosmological constant problems: (i) why the vacuum energy is so small and (ii) why it comes to dominate at about the epoch of galaxy formation. Anthropic selection appears to be the only approach that can naturally resolve…

High Energy Physics - Theory · Physics 2007-06-20 Alexander Vilenkin

Suppose that the early Universe starts with a quantum spacetime originated cosmological $\Lambda$-term at the Planck scale $M_{\rm pl}$. The cosmological energy density $\rho_{_{_\Lambda}}$ drives inflation and simultaneously reduces its…

General Relativity and Quantum Cosmology · Physics 2021-04-27 She-Sheng Xue

Models of open inflation with a variable density parameter $\Omega$ provide the most natural way to reconcile an open universe with inflation. The use of anthropic principle is essential to derive observational predictions of such models. I…

Astrophysics · Physics 2011-04-15 Alexander Vilenkin

We compute trivariate probability distributions in the landscape, scanning simultaneously over the cosmological constant, the primordial density contrast, and spatial curvature. We consider two different measures for regulating the…

High Energy Physics - Theory · Physics 2010-04-29 Raphael Bousso , Stefan Leichenauer

The old cosmological constant problem is to understand why the vacuum energy is so small; the new problem is to understand why it is comparable to the present mass density. Several approaches to these problems are reviewed. Quintessence…

Astrophysics · Physics 2007-05-23 Steven Weinberg

Observational constraints guide one forcefully to examine models in which the matter density is substantially less than critical density. Particularly noteworthy are those which are consistent with inflation. For these models, microwave…

Astrophysics · Physics 2007-05-23 J. P. Ostriker , Paul J. Steinhardt

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

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Tarun Souradeep

If our observable Universe is only a tiny region of a vastly larger and conformally older spacetime, then the usual formulations of the classical flatness and horizon problems of the Hot Big Bang can be reinterpreted as artifacts…

General Relativity and Quantum Cosmology · Physics 2026-02-12 Meir Shimon

The anthropic principle is an inevitable constraint on the space of possible theories. As such it is central to determining the limits of physics. In particular, we contend that what is ultimately possible in physics is determined by…

General Relativity and Quantum Cosmology · Physics 2010-02-11 Navin Sivanandam

The place of an anthropic argument in the discrimination between various cosmological models is to be reconsidered following the classic criticisms of Paul C. W. Davies and Frank J. Tipler. Different versions of the anthropic argument…

Astrophysics · Physics 2009-11-11 Milan M. Cirkovic

Perhaps the deepest mystery of our accelerating Universe in expansion is the existence of a tiny and rigid cosmological constant, $\Lambda$. Its size is many orders of magnitude below the expected one in the standard model of particle…

General Relativity and Quantum Cosmology · Physics 2015-04-03 Joan Sola , Adria Gomez-Valent

In this Letter we examine the Multiverse theory and how it relates to the Anthropic Principle. Under the supposition of Eternal Inflation, the String Theory Landscape (STL) has reinvigorated the discussion of the Anthropic Principle. The…

Popular Physics · Physics 2011-04-01 Douglas F. Watson

The energy densities of matter and the vacuum are currently observed to be of the same order of magnitude: $(\Omega_{m 0} \approx 0.3) \sim (\Omega_{\Lambda 0} \approx 0.7)$. The cosmological window of time during which this occurs is…

Astrophysics · Physics 2009-11-13 Charles H. Lineweaver , Chas A. Egan

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 Anthropic Principle has been with us since the 1970s. This Principle is advanced to account for the "fine tuning" of the 25 constants of the Standard Model of Particle Physics. Were these constants very different, life could not exist.…

History and Philosophy of Physics · Physics 2022-05-26 Stuart Kauffman

Probably not, because there are lots of manifestly unanthropic ways of producing entropy. We demonstrate that the Causal Entropic Principle (CEP), as a replacement for the anthropic principle to explain the properties of the observed…

High Energy Physics - Theory · Physics 2008-12-05 Irit Maor , Thomas W. Kephart , Lawrence M. Krauss , Y. Jack Ng , Glenn D. Starkman

An anthropic explanation for evident smallness of the value of the dark energy implies the existence of a time-dependent component of the scalar field, serving, together with a negative-valued cosmological constant, as one of two components…

General Relativity and Quantum Cosmology · Physics 2020-01-08 A. A. Yurova , A. V. Yurov , V. A. Yurov

Prediction in quantum cosmology requires a specification of the universe's quantum dynamics and its quantum state. We expect only a few general features of the universe to be predicted with probabilities near unity conditioned on the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 James B. Hartle

The main argument that Universe is currently expanding is observed redshift increase by distance. However, this conclusion may not be correct, because cosmological redshift depends only on the scaling factors, the change in the size of the…

General Physics · Physics 2012-07-05 Branislav Vlahovic