Observational constraints on patch inflation in noncommutative spacetime
- Dipartimento di Fisica, Universita di Parma, Parco Area delle Scienze 7/A, I-43100 Parma (Italy)
- Department of Physics, Gunma National College of Technology, Gunma 371-8530 (Japan)
We study constraints on a number of patch inflationary models in noncommutative spacetime using a compilation of recent high-precision observational data. In particular, the four-dimensional general relativistic (GR) case, the Randall-Sundrum (RS), and the Gauss-Bonnet brane world scenarios are investigated by extending previous commutative analyses to the infrared limit of a maximally symmetric realization of the stringy uncertainty principle. The effect of spacetime noncommutativity modifies the standard consistency relation between the tensor spectral index and the tensor-to-scalar ratio. We perform likelihood analyses in terms of inflationary observables using new consistency relations and confront them with large-field inflationary models with potential V{proportional_to}{phi}{sup p} in two classes of noncommutative scenarios. We find a number of interesting results: (i) the quartic potential (p=4) is rescued from marginal rejection in the class 2 GR case, and (ii) steep inflation driven by an exponential potential (p{yields}{infinity}) is allowed in the class 1 RS case. Spacetime noncommutativity can lead to blue-tilted scalar and tensor spectra even for monomial potentials, thus opening up a possibility to explain the loss of power observed in cosmic microwave background anisotropies. We also explore patch inflation with a Dirac-Born-Infeld tachyon field and explicitly show that the associated likelihood analysis is equivalent to the one in the ordinary scalar field case by using horizon-flow parameters. It turns out that tachyon inflation is compatible with observations in all patch cosmologies even for large p.
- OSTI ID:
- 20697985
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 70, Issue 10; Other Information: DOI: 10.1103/PhysRevD.70.103514; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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