منابع مشابه
A note on inflation and transplanckian physics
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In this paper we investigate how the energy density due to a non-standard choice of initial vacuum affects the expansion of the universe during inflation. To do this we introduce source terms in the Friedmann equations making sure that we respect the relation between gravity and thermodynamics. We find that the energy production automatically implies a slow rolling cosmological constant. Hence ...
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The union of high-energy particle theories and gravitation often gives rise to an evolving strength of gravity. The standard picture of the earliest universe would certainly deserve revision if the Planck mass, which de nes the strength of gravity, varied. A notable consequence is a gravity-driven, kinetic in ation. Unlike standard in ation, there is no potential nor cosmological constant. The ...
متن کاملInflation from Quantum Gravity
In recent years cosmologists are repeatedly invoking quantum fluctuations to "explain" the origin of the universe [1 ]. We discuss here one such model in which our observed universe originates from a primordial "Planck size bubble" through inflation. The final state of the universe will have zero cosmological constant and zero spatial curvature with overwhelming probability. The analysis is bas...
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We consider the quantum gravitational back-reaction on an initially inflating, homogeneous and isotropic universe whose topology is T 3 × R. Although there is no secular effect at one loop, an explicit calculation shows that two-loop processes act to slow the rate of expansion by an amount which becomes non-perturbatively large at late times. By exploiting Feynman’s tree theorem we show that al...
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ژورنال
عنوان ژورنال: Physics Letters B
سال: 2015
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2015.07.018