Flow equations in generalized braneworld scenarios

Journal Article · Mon Aug 15 04:00:00 EDT 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.72.043513· OSTI ID:20711313

Calcagni, Gianluca; Liddle, Andrew R; Ramirez, Erandy ^[1]

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1. Department of Physics, Gunma National College of Technology, Gunma 371-8530 (Japan)

We discuss the flow equations in the context of general braneworld cosmologies with a modified Friedmann equation, for either an ordinary scalar field or a Dirac-Born-Infeld tachyon as inflaton candidates. The 4D, Randall-Sundrum, and Gauss-Bonnet cases are compared, using the patch formalism which provides a unified description of these models. The inflationary dynamics is described by a tower of flow parameters that can be evolved in time to select a particular subset of points in the space of cosmological observables. We analyze the stability of the fixed points in all the cosmologies (our results in the 4D case already extending those in the literature). Numerical integration of the flow equations shows that the predictions of the Gauss-Bonnet braneworld differ significantly as compared to the Randall-Sundrum and 4D scenarios, whereas tachyon inflation gives tensor perturbations smaller than those in the presence of a normal scalar field. These results are extended to the realization of a noncommutative space-time preserving maximal symmetry. In this case the tensor-to-scalar signal is unchanged, while blue-tilted spectra are favored.

• OSTI ID: 20711313
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 4 Vol. 72; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BORN-INFELD THEORY
COMMUTATION RELATIONS
COSMOLOGY
DISTURBANCES
GRAVITATION
INFLATIONARY UNIVERSE
SCALAR FIELDS
SPACE-TIME
SYMMETRY
TENSORS