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Abstract Quasiclassical methods are used to define dynamical tunneling times in models of quantum cosmological bounces. These methods provide relevant new information compared with the traditional treatment of quantum tunneling by means of tunneling probabilities. As shown here, the quantum dynamics in bounce models is not secure from reaching zero scale factor, re-opening the question of how the classical singularity may be avoided. Moreover, in the examples studied here, tunneling times remain small even for large barriers, highlighting the quantum instability of underlying bounce models.
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Quantum geometric formulation of Brans-Dicke theory for Bianchi I spacetime
We consider a formulation of the Brans-Dicke theory in Jordan's frame for Bianchi-I spacetime within the framework of loop quantum gravity. The robustness of singularity resolutions due to the quantum effects is explicitly verified in the context of two quantization schemes typically used in the literature. We present an exploration of the effects of quantum geometry on the background dynamics, which is also illustrated through some explicit numerical examples and showing the absence of the singularity.
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- Award ID(s):
- 2308845
- PAR ID:
- 10569135
- Publisher / Repository:
- Cornell University
- Date Published:
- Journal Name:
- ArXiv
- ISSN:
- 1133-3774
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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