Abstract
It is shown that the inflationary era in early universe is realized due to the effect of backreaction of quantized matter fields. In fact we start by quantizing a free scalar field in the Friedmann-Robertson-Walker space-time, and the field is fluctuating quantum mechanically around the bottom of the mass potential. We then obtain the vacuum expectation value of the energy density of the scalar field as a functional of the scale factor a(t) of the universe. By plugging it into the Einstein equation, a self-consistent equation is established in which the matter fields determine the time evolution of the universe. We solve this equation by setting few conditions and find the following solution: the universe expands à la de Sitter with e-folding number ≳ 60 and then it turns to shrink with a decreasing Hubble parameter H(t) which rapidly goes to zero.
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References
A.H. Guth, The Inflationary Universe: A Possible Solution to the Horizon and Flatness Problems, Phys. Rev. D 23 (1981) 347 [INSPIRE].
WMAP collaboration, E. Komatsu et al., Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation, Astrophys. J. Suppl. 192 (2011) 18 [arXiv:1001.4538] [INSPIRE].
Planck collaboration, P.A.R. Ade et al., Planck 2013 results. I. Overview of products and scientific results, Astron. Astrophys. 571 (2014) A1 [arXiv:1303.5062] [INSPIRE].
Planck collaboration, P.A.R. Ade et al., Planck 2013 Results. XXIV. Constraints on primordial non-Gaussianity, Astron. Astrophys. 571 (2014) A24 [arXiv:1303.5084] [INSPIRE].
BICEP2 collaboration, P.A.R. Ade et al., Detection of B-Mode Polarization at Degree Angular Scales by BICEP2, Phys. Rev. Lett. 112 (2014) 241101 [arXiv:1403.3985] [INSPIRE].
R.K. Sachs and A.M. Wolfe, Perturbations of a cosmological model and angular variations of the microwave background, Astrophys. J. 147 (1967) 73 [Gen. Rel. Grav. 39 (2007) 1929] [INSPIRE].
A.D. Linde, A New Inflationary Universe Scenario: A Possible Solution of the Horizon, Flatness, Homogeneity, Isotropy and Primordial Monopole Problems, Phys. Lett. B 108 (1982) 389 [INSPIRE].
A. Albrecht and P.J. Steinhardt, Cosmology for Grand Unified Theories with Radiatively Induced Symmetry Breaking, Phys. Rev. Lett. 48 (1982) 1220 [INSPIRE].
A.D. Linde, Chaotic Inflation, Phys. Lett. B 129 (1983) 177 [INSPIRE].
A.A. Starobinsky, A New Type of Isotropic Cosmological Models Without Singularity, Phys. Lett. B 91 (1980) 99 [INSPIRE].
N.P. Myhrvold, The Existence and Stability of Semiclassical de Sitter and Anti-de Sitter Space-times, Phys. Lett. B 132 (1983) 308 [INSPIRE].
E. Mottola, Particle Creation in de Sitter Space, Phys. Rev. D 31 (1985) 754 [INSPIRE].
I. Antoniadis, J. Iliopoulos and T.N. Tomaras, Quantum Instability of de Sitter Space, Phys. Rev. Lett. 56 (1986) 1319 [INSPIRE].
Y. Habara, H. Kawai, M. Ninomiya and Y. Sekino, CMB Fluctuations and String Compactification Scales, Phys. Lett. B 707 (2012) 198 [arXiv:1103.0299] [INSPIRE].
Y. Habara, H. Kawai, M. Ninomiya and Y. Sekino, Possible origin of CMB temperature fluctuations: Vacuum fluctuations of Kaluza-Klein and string states during inflationary era, Phys. Rev. D 85 (2012) 104027 [arXiv:1110.5392] [INSPIRE].
A. Kaya, Cosmological Evolution of Vacuum and Cosmic Acceleration, Class. Quant. Grav. 27 (2010) 235022 [arXiv:1006.0559] [INSPIRE].
A. Kaya and M. Tarman, Cosmological backreaction of a quantized massless scalar field, JCAP 01 (2012) 040 [arXiv:1111.2511] [INSPIRE].
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ArXiv ePrint: 1410.0644
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Habara, Y., Kawai, H. & Ninomiya, M. A new mechanism of realizing inflationary universe with recourse to backreaction of quantized free fields — Inflation without inflaton —. J. High Energ. Phys. 2015, 148 (2015). https://doi.org/10.1007/JHEP02(2015)148
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DOI: https://doi.org/10.1007/JHEP02(2015)148