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Related papers: Why anthropic reasoning cannot predict Lambda

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A modern assessment of the classical Boltzmann-Schuetz argument for large-scale entropy fluctuations as the origin of our observable cosmological domain is given. The emphasis is put on the central implication of this picture which flatly…

History and Philosophy of Physics · Physics 2007-05-23 Milan M. Cirkovic

It is possible that the scale of gravity, parameterized by the apparent Planck mass, may obtain different values within different universes in an encompassing multiverse. We investigate the range over which the Planck mass may scan while…

Astrophysics · Physics 2008-11-26 Michael L. Graesser , Michael P. Salem

The anthropic principle implies that life can emerge and be sustained only in a narrow range of values of fundamental constants. Here we show that anthropic arguments can set powerful constraints on {\em transient} variations of the…

The causal entropic principle has been proposed as a superior alternative to the anthropic principle for understanding the magnitude of the cosmological constant. In this approach, the probability to create observers is assumed to be…

High Energy Physics - Theory · Physics 2008-11-26 James M. Cline , Andrew R. Frey , Gilbert Holder

We compute the expected value of the cosmological constant in our universe from the Causal Entropic Principle. Since observers must obey the laws of thermodynamics and causality, the principle asserts that physical parameters are most…

High Energy Physics - Theory · Physics 2008-11-26 Raphael Bousso , Roni Harnik , Graham D. Kribs , Gilad Perez

We utilize anthropic reasoning to demonstrate that we are typical observers of our reference class under a self-sampling assumption by investigating the definition of what a civilization is. With reference to the conflict between such…

Physics and Society · Physics 2007-05-23 Kevin A. Pimbblet

In the context of models where the dark energy density $\rD$ is a random variable, anthropic selection effects may explain both the "old" cosmological constant problem and the "time coincidence". We argue that this type of solution to both…

Astrophysics · Physics 2009-11-07 J. Garriga , A. Vilenkin

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

This paper evaluates some important aspects of the multiverse concept. Firstly, the most realistic opportunity for it which is the spacetime variability of the physical constants and may deliver worlds with different physics, hopefully…

History and Philosophy of Physics · Physics 2019-10-22 Mariusz P. Dabrowski

The existence of multiple regions of space beyond the observable Universe (within the so-called "multiverse") where the vacuum energy density takes different values, has been postulated as an explanation for the low non-zero value observed…

Astrophysics · Physics 2009-11-11 Abraham Loeb

After reviewing the cosmological constant problem - why is Lambda not huge? - I outline the two basic approaches that had emerged by the late 1980s, and note that each made a clear prediction. Precision cosmological experiments now indicate…

High Energy Physics - Theory · Physics 2007-05-23 Raphael Bousso

We suggest to combine the Anthropic Principle with Many-Worlds Interpretation of Quantum Theory. Realizing the multiplicity of worlds it provides an opportunity of explanation of some important events which are assumed to be extremely…

Quantum Physics · Physics 2014-11-18 Alexander Kamenshchik , Oleg Teryaev

Efforts to understand the origin of the cosmological constant {\Lambda} and its observed value have led to consider it as a dynamical field rather than as a universal constant. Then the possibility arises that the universe, or regions of…

High Energy Physics - Theory · Physics 2015-06-23 Claudio Bunster , Alfredo Perez

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

Motivated by recent work of Bousso and Polchinski (BP), we study theories which explain the small value of the cosmological constant using the anthropic principle. We argue that simultaneous solution of the gauge hierarchy problem is a…

High Energy Physics - Theory · Physics 2010-02-03 Tom Banks , Michael Dine , Lubos Motl

In the modern quantum mechanics of cosmology observers are physical systems within the universe. They have no preferred role in the formulation of the theory nor in its predictions of third person probabilities of what occurs. However,…

General Relativity and Quantum Cosmology · Physics 2018-01-18 James Hartle , Thomas Hertog

It can be argued that the ordinary description of the reversible quantum process between two one-to-one correlated measurement outcomes is incomplete because, by not specifying the direction of causality, it allows causal structures that…

Quantum Physics · Physics 2023-11-02 Giuseppe Castagnoli

Modern scientific cosmology pushes the boundaries of knowledge and the knowable. This is prompting questions on the nature of scientific knowledge. A central issue is what defines a 'good' model. When addressing global properties of the…

History and Philosophy of Physics · Physics 2018-12-12 Martin Sahlén

We propose an approach to explaining why naive large quantum fluctuations are not the right estimate for the cosmological constant. We argue that the universe is in a superposition of many vacua, in such a way that the resulting…

High Energy Physics - Phenomenology · Physics 2009-11-10 G. L. Kane , M. J. Perry , A. N. Zytkow

We consider further consequences of recently [1] revealed role of cosmological constant \Lambda as of a physical constant, along with the gravitational one to define the gravity i.e. the General Relativity and its low-energy limit. We now…

General Physics · Physics 2019-03-13 V. G. Gurzadyan , A. Stepanian