Dynamics and chaos in the unified scalar field cosmology

Journal Article · Fri Feb 15 04:00:00 EST 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.77.043521· OSTI ID:21039109

Lukes-Gerakopoulos, Georgios ^[1]; Basilakos, Spyros; Contopoulos, George ^[1]

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1. Research Center for Astronomy, Academy of Athens, Soranou Efesiou 4, GR-11527, Athens (Greece)

We study the dynamics of the closed scalar field FRW cosmological models in the framework of the so-called unified dark matter (UDM) scenario. Performing a theoretical as well as a numerical analysis we find that there is a strong indication of chaos in agreement with previous studies. We find that a positive value of the spatial curvature is essential for the appearance of chaoticity, though the Lyapunov number seems to be independent of the curvature value. Models that are close to flat (k{yields}0{sup +}) exhibit a chaotic behavior after a long time while pure flat models do not exhibit any chaos. Moreover, we find that some of the semiflat models in the UDM scenario exhibit similar dynamical behavior with the {lambda} cosmology despite their chaoticity. Finally, we compare the measured evolution of the Hubble parameter derived from the differential ages of passively evolving galaxies with that expected in the semiflat unified scalar field cosmology. Based on a specific set of initial conditions we find that the UDM scalar field model matches well the observational data.

• OSTI ID: 21039109
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 4 Vol. 77; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHAOS THEORY
COMPARATIVE EVALUATIONS
COSMOLOGICAL MODELS
COSMOLOGY
LYAPUNOV METHOD
NONLUMINOUS MATTER
NUMERICAL ANALYSIS
SCALAR FIELDS
UNIFIED-FIELD THEORIES