scholarly journals A WAY TO DYNAMICALLY OVERCOME THE OLD COSMOLOGICAL CONSTANT PROBLEM

2008 ◽  
Vol 23 (25) ◽  
pp. 4133-4143 ◽  
Author(s):  
DENIS COMELLI
Keyword(s):  
Vector Field ◽  
Cosmological Constant ◽  
Total Derivative ◽  
Full Understanding ◽  
Cosmological Constant Problem ◽  
Effective Cosmological Constant ◽  
Present Universe

The old cosmological constant problem can be solved once we require that the full standard Einstein–Hilbert Lagrangian, gravity plus matter, is multiplied by a total derivative. We analyze such a picture writing the total derivative as the covariant gradient of a new vector field (bμ). Like in unimodular gravity, integration constants, regenerating an effective cosmological constant, can reenter into the game depending on the dynamics of the bμ field. In order to fit the present universe status without fine-tunings, a full understanding of the scales related to bμ field dynamics has to be settled down.

scholarly journals The Solution of the Cosmological Constant Problem: The Cosmological Constant Exponential Decrease in the Super-Early Universe

Universe ◽  
2020 ◽  
Vol 6 (12) ◽  
pp. 230
Author(s):  
Ol’ga Babourova ◽  
Boris Frolov
Keyword(s):  
Cosmological Constant ◽  
Big Bang ◽  
Cosmological Constant Problem ◽  
Scale Invariant ◽  
Weyl Space ◽  
Effective Cosmological Constant ◽  
Exponential Decrease ◽  
The Big Bang ◽  
Modern Era ◽  
Gauge Theory Of Gravity

The stage of a super-early (primordial) scale-invariant Universe is considered on the basis of the Poincaré–Weyl gauge theory of gravity in a Cartan–Weyl space-time. An approximate solution has been found that demonstrates an inflationary behavior of the scale factor and, at the same time, a sharp exponential decrease in the effective cosmological constant from a huge value at the beginning of the Big Bang to an extremely small (but not zero) value in the modern era, which solves the well-known “cosmological constant problem.”

scholarly journals The Solution of the Cosmological Constant Problem: The Cosmological Constant Exponential Decrease in the Super-Early Universe

2020 ◽  
Author(s):  
Ol'ga Babourova ◽  
Boris Frolov
Keyword(s):  
Cosmological Constant ◽  
Big Bang ◽  
Cosmological Constant Problem ◽  
Scale Invariant ◽  
Weyl Space ◽  
Effective Cosmological Constant ◽  
Exponential Decrease ◽  
The Big Bang ◽  
Modern Era ◽  
Gauge Theory Of Gravity

The stage of a super-early scale-invariant Universe is considered on the basis of the Poincaré–Weyl gauge theory of gravity in a Cartan–Weyl space-time. An approximate solution has been found that demonstrates an inflationary behavior of the scale factor and, at the same time, a sharp exponential decrease in the effective cosmological constant from a huge value at the beginning of the Big Bang to an extremely small (but not zero) value in the modern era, which solves the well-known “cosmological constant problem”.

scholarly journals Decrease of the effective cosmological constant in the Poincare gauge theory of gravity with a scalar field

2021 ◽  
Vol 2081 (1) ◽  
pp. 012015
Author(s):  
O V Babourova ◽  
B N Frolov
Keyword(s):  
Gauge Theory ◽  
Scalar Field ◽  
Cosmological Constant ◽  
Big Bang ◽  
Cosmological Constant Problem ◽  
Effective Cosmological Constant ◽  
Theory Of Gravity ◽  
The Big Bang ◽  
Modern Era ◽  
Gauge Theory Of Gravity

Abstract Cosmological consequences of the Poincare gauge theory of gravity are considered. An effective cosmological constant depending from the Dirac scalar field is introduced. It is proved that at the super-early Universe, the effective cosmological constant decreases exponentially from a huge value at the Big Bang to its extremely small value in the modern era, while the scale factor sharply increases and demonstrates inflationary behavior. This fact solves the well-known “cosmological constant problem” also in the Poincare gauge theory of gravity.

GAUGE CONDENSATES AND GAUGE DYNAMICS, THE COSMOLOGICAL AND STRONG CP PROBLEMS

1999 ◽  
Vol 14 (22) ◽  
pp. 3497-3530 ◽  
Author(s):  
E. I. GUENDELMAN
Keyword(s):  
Cosmological Constant ◽  
Gauge Field ◽  
Particle Physics ◽  
Gauge Fields ◽  
Total Derivative ◽  
Type Solution ◽  
Cosmological Constant Problem ◽  
First Order ◽  
True Vacuum ◽  
And Control

Some evidence for gauge field condensation in gauge theories is reviewed. The gravitational effects of gauge field condensates, in particular those associated with four-index field strengths are analyzed, paying special attention to their effect on the cosmological constant problem (CCP) and on the matching of different phases of the theory. Gauge fields composed of elementary scalars and their role in the CCP are studied. In particular such gauge fields can define a composite measure of integration which is a total derivative leading to the invariance under changes in the Lagrangian density L, L→L+ constant . In such models, when gravity is formulated in the first order formalism, gauge field condensates define and control particle physics dynamics and drive inflation while the true vacuum of the theory is one with zero cosmological constant. It is also shown that models of gauge fields composed of elementary scalars, like the "No Scale Nonlinear σ Model" can produce a new geometrical-type solution of the strong CP problem, which is possible when a condensate of a composite gauge field is present. It is shown that the theory without the cosmological constant problem explained here has a scale invariance, spontaneously broken by the expectation value of a four-index field strength. However, no massless "dilaton" appears as a result of this SSB.

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 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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