Evolution of curvature and anisotropy near a nonsingular bounce

Journal Article · Sat Oct 15 04:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.84.083520· OSTI ID:21607879

Bingkan, Xue ^[1]; Steinhardt, Paul J ^[1]

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1. Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)

We consider bouncing cosmologies in which an ekpyrotic contraction phase with w>>1 is followed by a bouncing phase with w<-1 that violates the null energy condition. The bouncing phase, induced by ghost condensation, is designed to produce a classically nonsingular bounce at a finite value of the scale factor. We show that the initial curvature and anisotropy, though diluted during the ekpyrotic phase, grow back exponentially during the bouncing phase. Moreover, curvature perturbations and anisotropy are generated by quantum fluctuations during the ekpyrotic phase. In the bouncing phase, however, an adiabatic curvature perturbation grows to dominate and contributes a blue spectrum that spoils the scale invariance. Meanwhile, a scalar shear perturbation grows nonlinear and creates an overwhelming anisotropy that disrupts the nonsingular bounce altogether.

• OSTI ID: 21607879
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 8 Vol. 84; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANISOTROPY
COSMOLOGY
DISTURBANCES
FLUCTUATIONS
INVARIANCE PRINCIPLES
NONLINEAR PROBLEMS
PERTURBATION THEORY
SCALE INVARIANCE
SPECTRA
VARIATIONS