Results 41 to 50 of about 48,479 (254)
, 1995 An exploratory study of the cosmology of moduli in string theory. Moduli are argued to be natural inflaton fields and lead to a robust inflationary cosmology in which inflation takes place at the top of domain walls. The amplitude of microwave background
A. Albrecht +54 more
core +2 more sources
Towards geometric inflation: The cubic case
Physics Letters B, 2020 We present an up to cubic curvature correction to General Relativity with the following features: (i) its vacuum spectrum solely consists of a graviton, (ii) it possesses well-behaved black hole solutions which coincide with those of Einsteinian cubic ...
Gustavo Arciniega +2 more
doaj +1 more source
Inflation and the cosmological constant [PDF]
Physical Review D, 2012 A particular compensation-type solution of the main cosmological constant problem has been proposed recently, with two massless vector fields dynamically canceling an arbitrary cosmological constant . The naive expectation is that such a compensation mechanism does not allow for the existence of an inflationary phase in the very early Universe ...
openaire +4 more sources
Novel vacuum conditions in inflationary collapse models
Physics Letters B, 2017 Within the framework of inflationary models that incorporate a spontaneous reduction of the wave function for the emergence of the seeds of cosmic structure, we study the effects on the primordial scalar power spectrum by choosing a novel initial quantum
Gabriel R. Bengochea, Gabriel León
doaj +1 more source
A new mechanism for freezing extra dimensions with higher-order curvature terms
Physics Letters B, 2020 We construct a model of higher dimensional cosmology in which extra dimensions are frozen by virtue of the cubic-order Lovelock gravity throughout the cosmic history from inflation to the present with radiation and matter-dominated regimes in between.
Hiroaki W.H. Tahara +2 more
doaj +1 more source
Universe, 2020 We investigate the ability of the exponential power-law inflation to be a phenomenologically correct model of the early universe. We study General Relativity (GR) scalar cosmology equations in Ivanov–Salopek–Bond (or Hamilton–Jacobi like) representation ...
Igor Fomin, Sergey Chervon
doaj +1 more source
Constant-roll inflation in brane induced gravity cosmology
European Physical Journal C: Particles and Fields, 2022 In this article we study a constant-roll inflationary model in the context of the DGP brane-world cosmology caused by a quintessence scalar field. We determine an analytical solution for the Friedman equation coupled to the equation of motion of the ...
A. Ravanpak, G. F. Fadakar
doaj +1 more source
Holographic cosmology and tachyon inflation [PDF]
International Journal of Modern Physics A, 2018 After a brief introduction to the AdS/CFT holography, a tachyon inflation will be discussed in the framework of holographic cosmology. The model is based on a holographic braneworld scenario with an effective tachyon field on a D3-brane located at the holographic bound of an asymptotic ADS5 bulk.
openaire +5 more sources
Inflation with a negative cosmological constant [PDF]
Physical Review D, 2009 We find a unique way of realizing inflation through cyclic phases in an universe with negative vacuum energy. According to the second law of thermodynamics entropy monotonically increases from cycle to cycle, typically by a constant factor. This means that the scale factor at the same energy density in consecutive cycles also increases by a constant ...
Anupam Mazumdar +2 more
openaire +4 more sources
Inflationary universe in loop quantum cosmology [PDF]
, 2007 Loop quantum cosmology provides a nice solution of avoiding the big bang singularity through a big bounce mechanism in the high energy region. In loop quantum cosmology an inflationary universe is emergent after the big bounce, no matter what matter ...
Ashtekar A +25 more
core +1 more source