Late-Time Mild Inflation --- a possible solution of dilemma: cosmic age and the Hubble parameter ---

Abstract

We explore the cosmological model in which a late-time mild inflation is realized after the star formation epoch. Non-vanishing curvature coupling of a classical boson field yields this mild inflation without a cosmological constant. Accordingly the lifetime of the present Universe is remarkably increased in our model. Thus we show that the present observed high value of the Hubble parameter $H_0\approx 70-80km/sec/Mpc$ is compatible with the age of the oldest stars $14\mathrm{Gyr}$ without introducing the cosmological constant or the open Universe model. Moreover in our model, the local Hubble parameter becomes larger than the global one. Thus we show that the present observed local Hubble parameter measured by using the Cepheid variables is compatible with the global Hubble parameter measured by using the Sunyaev-Zeldovich effect. We also examine the energy conditions, evolution of the effective gravitational constant and the nucleosynthesis process.

18 pages

Cited by in corpus (12)

• The Case for a Positive Cosmological Lambda-term
• Inflation and quintessence with nonminimal coupling
• The stability of modified gravity models
• Coupled oscillators as models of quintom dark energy
• A crucial ingredient of inflation
• Stagflation -- Bose-Einstein condensation in the early universe
• Coupled oscillators as models of phantom and scalar field cosmologies
• Generalized slow-roll inflation
• Non-chaotic dynamics in general-relativistic and scalar-tensor cosmology
• Tales of tails in cosmology
• Observational tests for oscillating expansion rate of the Universe
• Spatial Periodicity of Galaxy Number Counts, CMB Anisotropy, and SNIa Hubble Diagram Based on the Universe Accompanied by a Non-Minimally Coupled Scalar Field