scholarly journals Cosmic Acceleration and a Natural Solution to the Cosmological Constant Problem

2005 ◽  
pp. 33-46
Author(s):  
Philip D. Mannheim
Keyword(s):  
Cosmological Constant ◽  
Cosmic Acceleration ◽  
Cosmological Constant Problem ◽  
Natural Solution

scholarly journals Bootstrapped Newtonian Cosmology and the Cosmological Constant Problem

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 358
Author(s):  
Roberto Casadio ◽  
Andrea Giusti
Keyword(s):  
Black Holes ◽  
Cosmological Constant ◽  
Quantum Cosmology ◽  
Quantum Physics ◽  
Gravitational Interaction ◽  
Newtonian Gravity ◽  
Cosmological Constant Problem ◽  
Newtonian Cosmology ◽  
Natural Solution ◽  
The Impact

Bootstrapped Newtonian gravity was developed with the purpose of estimating the impact of quantum physics in the nonlinear regime of the gravitational interaction, akin to corpuscular models of black holes and inflation. In this work, we set the ground for extending the bootstrapped Newtonian picture to cosmological spaces. We further discuss how such models of quantum cosmology can lead to a natural solution to the cosmological constant problem.

scholarly journals Quantum Theory, Noncommutative Gravity, and the Cosmological Constant Problem

2009 ◽  
Vol 2009 ◽  
pp. 1-7
Author(s):  
T. P. Singh
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Cosmological Constant ◽  
Hubble Constant ◽  
Zero Point ◽  
Energy Scale ◽  
Cosmic Acceleration ◽  
Cosmological Constant Problem ◽  
Point Energy ◽  
Starting Point

The cosmological constant problem is principally concerned with trying to understand how the zero-point energy of quantum fields contributes to gravity. Here we take the approach that by addressing a fundamental unresolved issue in quantum theory, we can gain a better understanding of the problem. Our starting point is the observation that the notion of classical time is external to quantum mechanics. Hence there must exist an equivalent reformulation of quantum mechanics which does not refer to an external classical time. Such a reformulation is a limiting case of a more general quantum theory which becomes nonlinear on the Planck mass/energy scale. The nonlinearity gives rise to a quantum-classical duality which maps a “strongly quantum, weakly gravitational” dynamics to a “weakly quantum, strongly gravitational” dynamics. This duality predicts the existence of a tiny nonzero cosmological constant of the order of the square of the Hubble constant, which could be a possible source for the observed cosmic acceleration. Such a nonlinearity could also be responsible for the collapse of the wave function during a quantum measurement.

scholarly journals Constraining the Swiss-Cheese IR-Fixed Point Cosmology with Cosmic Expansion

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 263
Author(s):  
Ayan Mitra ◽  
Vasilios Zarikas ◽  
Alfio Bonanno ◽  
Michael Good ◽  
Ertan Güdekli
Keyword(s):  
Fixed Point ◽  
Cosmological Constant ◽  
Cosmic Acceleration ◽  
Fine Tuning ◽  
Clusters Of Galaxies ◽  
Swiss Cheese ◽  
Coincidence Problem ◽  
Cosmological Expansion ◽  
Cosmic Evolution ◽  
Previous Assumption

A recent work proposed that the recent cosmic passage to a cosmic acceleration era is the result of the existence of small anti-gravity sources in each galaxy and clusters of galaxies. In particular, a Swiss-cheese cosmology model, which relativistically integrates the contribution of all these anti-gravity sources on a galactic scale has been constructed assuming the presence of an infrared fixed point for a scale dependent cosmological constant. The derived cosmological expansion provides an explanation for both the fine tuning and the coincidence problem. The present work relaxes the previous assumption on the running of the cosmological constant and allows for a generic scaling around the infrared fixed point. Our analysis reveals that, in order to produce a cosmic evolution consistent with the best ΛCDM model, the IR-running of the cosmological constant is consistent with the presence of an IR-fixed point.

scholarly journals TIME, VACUUM ENERGY, AND THE COSMOLOGICAL CONSTANT

2009 ◽  
Vol 18 (14) ◽  
pp. 2265-2268 ◽  
Author(s):  
VIQAR HUSAIN
Keyword(s):  
Quantum Gravity ◽  
Cosmological Constant ◽  
Vacuum Energy ◽  
Cosmological Constant Problem ◽  
Problem Of Time ◽  
The Relationship

We describe a link between the cosmological constant problem and the problem of time in quantum gravity. This arises from examining the relationship between the cosmological constant and vacuum energy in light of nonperturbative formulations of quantum gravity.

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