scholarly journals Implications of a decay law for the cosmological constant in higher dimensional cosmology and cosmological wormholes

2009 ◽  
Vol 39 (3) ◽  
pp. 574-582 ◽  
Author(s):  
El-Nabulsi Ahmad Rami
Keyword(s):  
Cosmological Constant ◽  
Higher Dimensional Cosmology ◽  
Higher Dimensional

scholarly journals Gravitational Theory Without the Cosmological Constant Problem

1997 ◽  
Vol 12 (32) ◽  
pp. 2421-2424 ◽  
Author(s):  
E. I. Guendelman ◽  
A. B. Kaganovich
Keyword(s):  
Cosmological Constant ◽  
Degrees Of Freedom ◽  
Vacuum Energy ◽  
Dimensional Space ◽  
Realistic Model ◽  
Gravitational Theory ◽  
Space Time ◽  
Higher Dimensional Space Time ◽  
Higher Dimensional ◽  
Dimensional Space Time

We develop a gravitational theory where the measure of integration in the action principle is not necessarily [Formula: see text] but it is determined dynamically through additional degrees of freedom. This theory is based on the demand that such measure respects the principle of "non-gravitating vacuum energy" which states that the Lagrangian density L can be changed to L + const. without affecting the dynamics. Formulating the theory in the first-order formalism we get as a consequence of the variational principle a constraint that enforces the vanishing of the cosmological constant. The most realistic model that implements these ideas is realized in a six or higher dimensional space–time. The compactification of extra dimensions into a sphere gives the possibility of generating scalar masses and potentials, gauge fields and fermionic masses. It turns out that the remaining four-dimensional space–time must have effective zero cosmological constant.

scholarly journals New gedanken experiment on higher-dimensional asymptotically AdS Reissner–Nordström black hole

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Ming Zhang ◽  
Jie Jiang
Keyword(s):  
Black Hole ◽  
Cosmological Constant ◽  
Order Approximation ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Matter Field ◽  
Second Order ◽  
Field Perturbation ◽  
Higher Dimensional ◽  
Dynamical Quantity

AbstractViewing the negative cosmological constant as a dynamical quantity derived from the matter field, we study the weak cosmic censorship conjecture for the higher-dimensional asymptotically AdS Reissner–Nordström black hole. To this end, using the stability assumption of the matter field perturbation and the null energy condition of the matter field, we first derive the first-order and second-order perturbation inequalities containing the variable cosmological constant and its conjugate quantity for the black hole. We prove that the higher-dimensional RN-AdS black hole cannot be destroyed under a second-order approximation of the matter field perturbation process.

HIGHER DIMENSIONAL COSMOLOGY WITH STRING VACUUM ENERGY

1987 ◽  
Vol 02 (05) ◽  
pp. 299-306 ◽  
Author(s):  
H. NISHIMURA ◽  
M. TABUSE
Keyword(s):  
String Theory ◽  
Vacuum Energy ◽  
Bosonic String ◽  
Extra Space ◽  
Higher Dimensional Cosmology ◽  
Higher Dimensional ◽  
Bosonic String Theory ◽  
The One ◽  
Closed Bosonic String

We consider higher dimensional cosmology based on the closed bosonic string theory with the one-loop vacuum energy. It is concluded that the winding-effect of strings around tori has a chance to prevent the extra space from expanding, even though the curvature of torus is zero.

scholarly journals MULTI-DIMENSIONAL COSMOLOGY AND DSR–GUP

2013 ◽  
Vol 28 (12) ◽  
pp. 1350047 ◽  
Author(s):  
K. ZEYNALI ◽  
F. DARABI ◽  
H. MOTAVALLI
Keyword(s):  
Cosmological Constant ◽  
Generalized Uncertainty Principle ◽  
Internal Space ◽  
Positive Cosmological Constant ◽  
Doubly Special Relativity ◽  
Dimensional Spacetime ◽  
Higher Dimensional ◽  
Big Crunch ◽  
The Difference ◽  
Cosmological Constants

A multi-dimensional cosmology with FRW type metric having four-dimensional spacetime and d-dimensional Ricci-flat internal space is considered with a higher-dimensional cosmological constant. The classical cosmology in commutative and Doubly Special Relativity–Generalized Uncertainty Principle (DSR–GUP) contexts is studied and the corresponding exact solutions for negative and positive cosmological constants are obtained. In the positive cosmological constant case, it is shown that unlike the commutative as well as GUP cases, in DSR–GUP case both scale factors of internal and external spaces after accelerating phase will inevitably experience decelerating phase leading simultaneously to a big crunch. This demarcation from GUP originates from the difference between the GUP and DSR–GUP algebras. The important result is that unlike GUP which results in eternal acceleration, DSR–GUP at first generates acceleration but prevents the eternal acceleration at late-times and turns it into deceleration.

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