Analysis of scalar perturbations in cosmological models with a non-local scalar field

Koshelev, Alexey S.; Vernov, S. Yu.

doi:10.1088/0264-9381/28/8/085019

Cited by 28 publications

(21 citation statements)

References 104 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Let us therefore write a local realization of (3). Originally, this was done in [32] and then formalized in [33,34,37]. We use the Weierstrass factorization [32] which prescribes that any entire function (we recall that SFT ensures that operators F ( ) are analytic functions and in all existing computations they appear to be entire functions) can be written as…”

Section: Effective Fields From a Non-local Frameworkmentioning

confidence: 99%

Effective models of inflation from a nonlocal framework

Koshelev¹,

Kumar

Moniz

2017

Phys. Rev. D

View full text Add to dashboard Cite

The dilaton is a possible inflaton candidate following recent CMB data allowing a non-minimal coupling to the Ricci curvature scalar in the early Universe. In this paper, we introduce an approach that has seldom been used in the literature, namely dilaton inflation with non-local features. More concretely, employing non-local features expressed in J. High Energy Phys. 04 (2007) 029, we study quadratic variations around a de Sitter geometry of an effective action with a non-local dilaton. The non-locality refers to an infinite derivative kinetic term involving the operator F ( ). Algebraic roots of the characteristic equation F(z) = 0 play a crucial role in determining the properties of the theory. We subsequently study the cases when F ( ) has one real root and one complex root, from which we retrieve two concrete effective models of inflation. In the first case we retrieve a class of single field inflations with universal prediction of ns ∼ 0.967 with any value of the tensor to scalar ratio r < 0.1 intrinsically controlled by the root of the characteristic equation. The second case involves a new class of two field conformally invariant models with a peculiar quadratic cross-product of scalar fields. In this latter case, we obtain Starobinsky like inflation through a spontaneously broken conformal invariance. Furthermore, an uplifted minimum of the potential, which accounts for the vacuum energy after inflation is produced naturally through this mechanism intrinsically within our approach.

show abstract

Section: Effective Fields From a Non-local Frameworkmentioning

confidence: 99%

Effective models of inflation from a nonlocal framework

Koshelev¹,

Kumar

Moniz

2017

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…[4,6,19,7,52,38,39]). String field theory and p-adic string theory models have played significant role in motivation and construction of such models.…”

Section: Discussionmentioning

confidence: 99%

On Nonlocal Modified Gravity and Its Cosmological Solutions

Dimitrijevic

Драгович

Stanković

et al. 2016

Springer Proceedings in Mathematics &Amp; Statistics

View full text Add to dashboard Cite

During hundred years of General Relativity (GR), many significant gravitational phenomena have been predicted and discovered. General Relativity is still the best theory of gravity. Nevertheless, some (quantum) theoretical and (astrophysical and cosmological) phenomenological difficulties of modern gravity have been motivation to search more general theory of gravity than GR. As a result, many modifications of GR have been considered. One of promising recent investigations is Nonlocal Modified Gravity. In this article we present a brief review of some nonlocal gravity models with their cosmological solutions, in which nonlocality is expressed by an analytic function of the d'Alembert-Beltrami operator . Some new results are also presented.

show abstract

“…In the case of a quadratic potential a cosmological model with one nonlocal scalar field can be presented as a model with local scalar fields and quadratic potentials [22,23,24,29,34,36,37]. For this model it has been observed [25,26] that in the regime suitable for the Early Universe the effect of the effective stretch of the kinetic terms takes place (see also [24,29]).…”

Section: Non-positively Defined Potentials As a Consequence Of Nonlocmentioning

confidence: 99%

Friedmann cosmology with nonpositive-definite Higgs potentials

2012

View full text Add to dashboard Cite

We discuss the classical aspects of dynamics of scalar models with non-positive Higgs potentials in the FRW cosmology. These models appear as effective local models in non-local models related with string field theories. After a suitable field redefinition these models have the form of local Higgs models with a negative extra cosmological term and the total Higgs potential is non-positively defined and has rather small coupling constant. The non-positivity of the potential leads to the fact that on some stage of evolution the expansion mode gives place to the mode of contraction, due to that the stage of reheating is absent. In these models the hard regime of inflation gives place to inflation near the hill top and the area of the slow roll inflation is very small. Meanwhile one can obtain enough e-foldings before the contraction to make the model under consideration admissible to describe inflation. * arefeva@mi.ras.ru † nick bulatov@mail.ru ‡ rgorbachev@mi.ras.ru 1 arXiv:1112.5951v3 [hep-th]

show abstract

Analysis of scalar perturbations in cosmological models with a non-local scalar field

Cited by 28 publications

References 104 publications

Effective models of inflation from a nonlocal framework

Effective models of inflation from a nonlocal framework

On Nonlocal Modified Gravity and Its Cosmological Solutions

Friedmann cosmology with nonpositive-definite Higgs potentials

Contact Info

Product

Resources

About