scholarly journals Universal scattering laws for quiescent bouncing cosmology

2021 ◽  
Vol 103 (8) ◽  
Author(s):  
Bruno Le Floch ◽  
Philippe G. LeFloch ◽  
Gabriele Veneziano
Keyword(s):  
Bouncing Cosmology

scholarly journals Tracing primordial black holes in nonsingular bouncing cosmology

2017 ◽  
Vol 769 ◽  
pp. 561-568 ◽  
Author(s):  
Jie-Wen Chen ◽  
Junyu Liu ◽  
Hao-Lan Xu ◽  
Yi-Fu Cai
Keyword(s):  
Black Holes ◽  
Primordial Black Holes ◽  
Bouncing Cosmology

scholarly journals Specific entropy as a clock for the evolutionary quantization of the isotropic Universe

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Andrea Campolongo ◽  
Giovanni Montani
Keyword(s):  
Constant Term ◽  
Hamiltonian Operator ◽  
Closed Universe ◽  
Classical Dynamics ◽  
Cosmological Singularity ◽  
Quantum Regime ◽  
Bouncing Cosmology ◽  
Forbidden Region ◽  
The One ◽  
Quantum Mechanical Approach

AbstractIn this paper, we analyze the dynamics of an isotropic closed Universe in presence of a cosmological constant term and we compare its behavior in the standard Wheeler–DeWitt equation approach with the one when a Lagrangian fluid is considered in the spirit of the Kuchar–Brown paradigm. In particular, we compare the tunnelling of the Universe from the classically forbidden region to the allowed one, showing that considering a time evolution deeply influences the nature of the model. In fact, we show that in the presence of the Lagrangian fluid, the cosmological singularity is restored both in the classical and the quantum regime. However, in the quantum regime the singularity is probabilistically suppressed for some energy eigenvalues and in the case the latter is equal to zero one recovers the standard WDW case. Finally, we introduce a cut-off physics feature in the Minisuperspace by considering a Polymer quantum mechanical approach limiting our attention to the semi-classical dynamics mainly (the quantum treatment is inhibited by the non-local nature of the Hamiltonian operator). We show that the singularity is again removed, like in the fluid-free model, and a bouncing cosmology emerges so that the present model could mimic a cyclic cosmology.

scholarly journals Bouncing cosmology in f(R,G) gravity by order reduction

2020 ◽  
Vol 419 ◽  
pp. 168231
Author(s):  
Bruno J. Barros ◽  
Elsa M. Teixeira ◽  
Daniele Vernieri
Keyword(s):  
Order Reduction ◽  
Bouncing Cosmology

scholarly journals Bouncing cosmology made simple

2018 ◽  
Vol 35 (13) ◽  
pp. 135004 ◽  
Author(s):  
Anna Ijjas ◽  
Paul J Steinhardt
Keyword(s):  
Bouncing Cosmology

scholarly journals Nonsingular cosmology from an unstable Higgs field

2017 ◽  
Vol 26 (01) ◽  
pp. 1740006 ◽  
Author(s):  
Robert H. Brandenberger ◽  
Yi-Fu Cai ◽  
Youping Wan ◽  
Xinmin Zhang
Keyword(s):  
Higgs Mass ◽  
Higgs Field ◽  
High Energy ◽  
Large Field ◽  
Bouncing Cosmology ◽  
Very High Energy ◽  
Contracting Phase ◽  
Early Universe Cosmology ◽  
Very High ◽  
Higgs Scalar

The observed value of the Higgs mass indicates an instability of the Higgs scalar at large energy scales, and hence also at large field values. In the context of early universe cosmology, this is often considered to lead to problems. Here, we point out that we can use the instability of the Higgs field to generate an ekpyrotic phase of contraction. In the context of string theory, it is possible that at very high energy densities, extra states become massless leading to an [Formula: see text]-brane which causes the transition between a contracting phase in the past and the current expanding phase. Thus, the Higgs field may be useable to generate a nonsingular bouncing cosmology in which the anisotropy problem of usual bouncing scenarios is mitigated.

Sign in / Sign up

Export Citation Format

Share Document