Bouncing Braneworlds

By Y. Shtanov, V. Sahni. 2002

176 citations recorded by the source corpus.

We study cosmological braneworld models with a single timelike extra dimension. Such models admit the intriguing possibility that a contracting braneworld experiences a natural bounce without ever reaching a singular state. This feature persists in the case of anisotropic braneworlds under some additional and not very restrictive assumptions. Generalizing our study to braneworld models containing an induced brane curvature term, we ﬁnd that a FRW-type singularity is once again absent if the bulk extra dimension is timelike. In this case, the universe either has a non-singular origin or com-mences its expansion from a quasi-singular state during which both the Hubble parameter and the energy density and pressure remain ﬁnite while the curvature tensor diverges. The non-singular and quasi-singular behaviour which we have discovered diﬀers both qualitatively and quantitatively from what is usually observed in braneworld models with spacelike extra dimensions and could have interesting cosmological implications.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/a656e7c687e817c9b9f86ffd48fc090889e0f83c

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Citations in the corpus

Brane-World Gravity (2004, background): “1 We do not consider timelike extra dimensions: see [393] for an interesting example.”
Quantum nature of the big bang: An analytical and numerical investigation (2006, background): “One way to reverse the sign is to introduce a second time-like dimension in the bulk [77].”
Loop quantum cosmology: a status report (2011, background): “Therefore in the brane world scenarios bounces can occur only if the brane tension is allowed to be negative [204].”
Viscous Cosmology for Early- and Late-Time Universe (2017, methodology): “Such models have been constructed in modified gravity constructions, such as in the Pre-Big-Bang [140] and in the Ekpyrotic [141] scenarios, in f(R) gravity [142–144], in f(T ) gravity [145], in braneworld scenarios [146, 147], in loop quantum cosmology [148, 149] etc.”
Non-singular cosmology in a model of non-relativistic gravity (2009, methodology): “The scenario of bouncing cosmology has been investigated in models motivated by various approaches to quantum gravity [18–23], and analyzed using effective field techniques by introducing energy-condition-violating matters [11, 24–26], while the generation of perturbation was studied in [27–34] (and”