Results 31 to 40 of about 18,708 (249)
Journal of High Energy Physics, 2014 19 pages and 8 figures, v2: version published in ...
Ahmed, Aqeel +2 more
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NONSINGULAR COSMOLOGIES FROM BRANES [PDF]
International Journal of Modern Physics A, 2004 We analyze possible cosmological scenarios on a brane where the brane acts as a dynamical boundary of various black holes with anti-de Sitter or de Sitter asymptotic. In many cases, the brane is found to describe the completely nonsingular universe. In some cases, quantum gravity era of the brane-universe can also be avoided by properly tuning bulk ...
Biswas, Anindya +2 more
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Mass Hierarchies and Quantum Gravity Constraints in DKMM‐refined KKLT
Fortschritte der Physik, Volume 71, Issue 1, January 2023., 2023 Abstract We carefully revisit the mass hierarchies for the KKLT scenario with an uplift term from an anti D3‐brane in a strongly warped throat. First, we derive the bound resulting from what is usually termed “the throat fitting into the bulk” directly from the Klebanov‐Strassler geometry.
Ralph Blumenhagen +2 more
wiley +1 more source
Cosmological 3-brane solutions [PDF]
Physics Letters B, 1999 We analyze cosmological equations in the brane world scenario with one extra space-like dimension. We demonstrate that the cosmological equations can be reduced to the usual 4D Friedmann type if the bulk energy-momentum tensor is different from zero. We then generalize these equations to the case of a brane of finite thickness. We also demonstrate that
Kanti, Panagiota +3 more
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Breeding Realistic D‐Brane Models
Fortschritte der Physik, Volume 70, Issue 5, May 2022., 2022 Abstract Intersecting branes provide a useful mechanism to construct particle physics models from string theory with a wide variety of desirable characteristics. The landscape of such models can be enormous, and navigating towards regions which are most phenomenologically interesting is potentially challenging.
Gregory J. Loges, Gary Shiu
wiley +1 more source
Varying Constants, Gravitation and Cosmology [PDF]
Living Reviews in Relativity, 2011 Uzan JP.
exaly +2 more sources
Journal of Cosmology and Astroparticle Physics, 2014 Disformally coupled cosmologies arise from Dirac-Born-Infeld actions in Type II string theories, when matter resides on a moving hidden sector D-brane. Since such matter interacts only very weakly with the standard model particles, this scenario can provide a natural origin for the dark sector of the universe with a clear geometrical interpretation ...
Koivisto, Tomi +2 more
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Quintessence and the Swampland: The Numerically Controlled Regime of Moduli Space
Fortschritte der Physik, Volume 70, Issue 4, April 2022., 2022 Abstract We provide a detailed discussion of the main theoretical and phenomenological challenges of quintessence model building in any numerically controlled regime of the moduli space of string theory. We argue that a working quintessence model requires a leading order non‐supersymmetric (near) Minkowski vacuum with an axionic flat direction.
Michele Cicoli +3 more
wiley +1 more source
Advances in High Energy Physics, Volume 2022, Issue 1, 2022., 2022 In this paper, we have investigated the density perturbations and cosmological evolution in the FLRW universe in the presence of a cosmic magnetic field, which may be assumed to mimic primordial magnetic fields. Such magnetic fields have sufficient strength to influence galaxy formation and cluster dynamics, thereby leaving an imprint on the CMB ...
Samarjit Chakraborty +2 more
wiley +1 more source
Some Bianchi Type Viscous Holographic Dark Energy Cosmological Models in the Brans–Dicke Theory
Advances in Astronomy, Volume 2022, Issue 1, 2022., 2022 In this article, we analyze Bianchi type–II, VIII, and IX spatially homogeneous and anisotropic space‐times in the background of the Brans–Dicke theory of gravity within the framework of viscous holographic dark energy. To solve the field equations, we have used the relation between the metric potentials as R = Sn and the relation between the scalar ...
M. Vijaya Santhi +4 more
wiley +1 more source