scholarly journals Quintessential Inflation with Dynamical Higgs Generation as an Affine Gravity

2020 ◽  
Author(s):  
David Benisty ◽  
Eduardo Guendelman ◽  
Emil Nissimov ◽  
Svetlana Pacheva
Keyword(s):  
Scalar Field ◽  
Symmetry Breaking ◽  
Modified Gravity ◽  
Riemannian Metric ◽  
Explicit Representation ◽  
Inflationary Universe ◽  
Inflationary Model ◽  
Scale Invariant ◽  
Higgs Effect ◽  
Affine Gravity

First, we propose a scale-invariant modified gravity interacting with a neutral scalar inflaton and a Higgs-like SU(2) × U(1) iso-doublet scalar field based on the formalism of non-Riemannian (metric-independent) spacetime volume-elements. This model describes in the physical Einstein frame a quintessential inflationary scenario driven by the “inflaton” together with gravity-inflaton assisted dynamical spontaneous SU(2) × U(1) symmetry breaking in the post-inflationary universe, whereas SU(2) × U(1) symmetry remains intact in the inflationary epoch. Next, we find the explicit representation of the latter quintessential inflationary model with a dynamical Higgs effect as an Eddington-type purely affine gravity.

scholarly journals Quintessential Inflation with Dynamical Higgs Generation as an Affine Gravity

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 734 ◽  
Author(s):  
David Benisty ◽  
Eduardo I. Guendelman ◽  
Emil Nissimov ◽  
Svetlana Pacheva
Keyword(s):  
Scalar Field ◽  
Symmetry Breaking ◽  
Modified Gravity ◽  
Riemannian Metric ◽  
Explicit Representation ◽  
Inflationary Universe ◽  
Inflationary Model ◽  
Scale Invariant ◽  
Higgs Effect ◽  
Affine Gravity

First, we propose a scale-invariant modified gravity interacting with a neutral scalar inflaton and a Higgs-like S U ( 2 ) × U ( 1 ) iso-doublet scalar field based on the formalism of non-Riemannian (metric-independent) spacetime volume-elements. This model describes, in the physical Einstein frame, a quintessential inflationary scenario driven by the “inflaton” together with the gravity-“inflaton” assisted dynamical spontaneous S U ( 2 ) × U ( 1 ) symmetry breaking in the post-inflationary universe, whereas the S U ( 2 ) × U ( 1 ) symmetry remains intact in the inflationary epoch. Next, we find the explicit representation of the latter quintessential inflationary model with a dynamical Higgs effect as an Eddington-type purely affine gravity.

scholarly journals Quintessential Inflation with Dynamical Higgs Generation as an Affine Gravity

2020 ◽  
Author(s):  
David Benisty ◽  
Eduardo Guendelman ◽  
Emil Nissimov ◽  
Svetlana Pacheva
Keyword(s):  
Scalar Field ◽  
Modified Gravity ◽  
Riemannian Metric ◽  
Explicit Representation ◽  
Inflationary Universe ◽  
Inflationary Model ◽  
Scale Invariant ◽  
Inflationary Scenario ◽  
Higgs Effect ◽  
Affine Gravity

First, we propose a scale-invariant modified gravity interacting with a neutral scalar inflaton and a Higgs-like SU(2)xU(1) iso-doublet scalar field based on the formalism of non-Riemannian (metric-independent) spacetime volume-elements. This model describes in the physical Einstein frame a quintessential inflationary scenario driven by the "inflaton" together with gravity-inflaton assisted dynamical spontaneous SU(2)xU(1) symmetry breaking in the post-inflationary universe, whereas SU(2)xU(1) symmetry remains intact in the inflationary epoch. Next, we find the explicit representation of the latter quintessential inflationary model with a dynamical Higgs effect as an Eddington-type purely affine gravity.

scholarly journals ONE-LOOP CALCULATION OF COSMOLOGICAL CONSTANT IN A SCALE INVARIANT THEORY

2009 ◽  
Vol 24 (26) ◽  
pp. 2069-2079 ◽  
Author(s):  
PANKAJ JAIN ◽  
SUBHADIP MITRA
Keyword(s):  
Field Theory ◽  
Scalar Field ◽  
Symmetry Breaking ◽  
Cosmological Constant ◽  
Invariant Theory ◽  
Scale Invariance ◽  
Constant Term ◽  
Scale Invariant ◽  
Gravitational Action ◽  
The One

We compute the cosmological constant in a scale invariant scalar field theory. The gravitational action is also suitably modified to respect scale invariance. Due to scale invariance, the theory does not admit a cosmological constant term. The scale invariance is broken by a recently introduced mechanism called cosmological symmetry breaking. This leads to a nonzero cosmological constant. We compute the one-loop corrections to the cosmological constant and show that it is finite.

scholarly journals Lattice simulations of inflation

2021 ◽  
Vol 2021 (12) ◽  
pp. 010
Author(s):  
Angelo Caravano ◽  
Eiichiro Komatsu ◽  
Kaloian D. Lozanov ◽  
Jochen Weller
Keyword(s):  
Scalar Field ◽  
Power Spectrum ◽  
Linear Perturbation ◽  
Inflationary Universe ◽  
Lattice Simulation ◽  
Scale Invariant ◽  
Step Potential ◽  
Lattice Codes ◽  
Linear Perturbation Theory ◽  
Single Field

Abstract The scalar field theory of cosmological inflation constitutes nowadays one of the preferred scenarios for the physics of the early universe. In this paper we aim at studying the inflationary universe making use of a numerical lattice simulation. Various lattice codes have been written in the last decades and have been extensively used for understating the reheating phase of the universe, but they have never been used to study the inflationary phase itself far from the end of inflation (i.e. about 50 e-folds before the end of inflation). In this paper we use a lattice simulation to reproduce the well-known results of some simple models of single-field inflation, particularly for the scalar field perturbation. The main model that we consider is the standard slow-roll inflation with an harmonic potential for the inflaton field. We explore the technical aspects that need to be accounted for in order to reproduce with precision the nearly scale invariant power spectrum of inflaton perturbations. We also consider the case of a step potential, and show that the simulation is able to correctly reproduce the oscillatory features in the power spectrum of this model. Even if a lattice simulation is not needed in these cases, that are well within the regime of validity of linear perturbation theory, this sets the basis to future work on using lattice simulations to study more complicated models of inflation.

scholarly journals A New Solution of Intermediate Cosmological Inflation with the Effect of Scalar Field

2021 ◽  
Vol 41 (1) ◽  
pp. 112-121
Author(s):  
Shomi Aktar ◽  
Anjan Kumar Chowdhury
Keyword(s):  
Scalar Field ◽  
Power Law ◽  
Equation Of Motion ◽  
Rapid Expansion ◽  
Inflationary Universe ◽  
Inflationary Model ◽  
Cosmological Inflation ◽  
The Universe ◽  
Interior Solutions

According to the inflationary model, the universe had a brief period of extraordinarily rapid expansion or inflation during which its diameter increased by a factor at least 1025 times larger than previously thought. In this work an analysis is given on inflationary universe, which expands at a rate intermediate between that of power-law and exponential inflation. We have examined the model of Barrow which is solved exactly and leaded to power law inflation. We have tested a new potential by applying the scalar field using the equation of motion and found some new interior solutions. The Chittagong Univ. J. Sci. 40(1) : 112-121, 2019

scholarly journals Scale Invariance, Horizons, and Inflation

2021 ◽  
Author(s):  
Andre Maeder ◽  
Vesselin G Gueorguiev
Keyword(s):  
Scalar Field ◽  
Scale Invariance ◽  
Maxwell Equations ◽  
High Redshift ◽  
Empty Space ◽  
Causal Connection ◽  
Cosmological Constant Problem ◽  
Scale Invariant ◽  
Starting Point ◽  
Final Answer

Abstract Maxwell equations and the equations of General Relativity are scale invariant in empty space. The presence of charge or currents in electromagnetism or the presence of matter in cosmology are preventing scale invariance. The question arises on how much matter within the horizon is necessary to kill scale invariance. The scale invariant field equation, first written by Dirac in 1973 and then revisited by Canuto et al. in 1977, provides the starting point to address this question. The resulting cosmological models show that, as soon as matter is present, the effects of scale invariance rapidly decline from ϱ = 0 to ϱc, and are forbidden for densities above ϱc. The absence of scale invariance in this case is consistent with considerations about causal connection. Below ϱc, scale invariance appears as an open possibility, which also depends on the occurrence of in the scale invariant context. In the present approach, we identify the scalar field of the empty space in the Scale Invariant Vacuum (SIV) context to the scalar field ϕ in the energy density $\varrho = \frac{1}{2} \dot{\varphi }^2 + V(\varphi )$ of the vacuum at inflation. This leads to some constraints on the potential. This identification also solves the so-called “cosmological constant problem”. In the framework of scale invariance, an inflation with a large number of e-foldings is also predicted. We conclude that scale invariance for models with densities below ϱc is an open possibility; the final answer may come from high redshift observations, where differences from the ΛCDM models appear.

scholarly journals Quantization of Einstein-aether scalar field cosmology

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
N. Dimakis ◽  
T. Pailas ◽  
A. Paliathanasis ◽  
G. Leon ◽  
Petros A. Terzis ◽  
...  
Keyword(s):  
Scalar Field ◽  
Classical Solution ◽  
Potential Function ◽  
Scalar Fields ◽  
Inflationary Model ◽  
Cosmological Theory ◽  
Local Functions ◽  
Arbitrary Potential ◽  
Scalar Field Cosmology ◽  
First Time

AbstractWe present, for the first time, the quantization process for the Einstein-aether scalar field cosmology. We consider a cosmological theory proposed as a Lorentz violating inflationary model, where the aether and scalar fields interact through the assumption that the aether action constants are ultra-local functions of the scalar field. For this specific theory there is a valid minisuperspace description which we use to quantize. For a particular relation between the two free functions entering the reduced Lagrangian the solution to the Wheeler–DeWitt equation as also the generic classical solution are presented for any given arbitrary potential function.

Andante regime of scalar field dynamics in the chaotic inflationary Universe

1995 ◽  
Vol 51 (2) ◽  
pp. 444-449 ◽  
Author(s):  
James E. Lidsey ◽  
I. Waga
Keyword(s):  
Scalar Field ◽  
Inflationary Universe ◽  
Scalar Field Dynamics

scholarly journals Polarized Initial States of Primordial Gravitational Waves

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 672
Author(s):  
Sugumi Kanno ◽  
Jiro Soda
Keyword(s):  
Gravitational Waves ◽  
Modified Gravity ◽  
Coherent States ◽  
Inflationary Universe ◽  
Dynamical Generation ◽  
Primordial Gravitational Waves ◽  
Initial States ◽  
Matter Fields

Polarizations of primordial gravitational waves can be relevant when considering an inflationary universe in modified gravity or when matter fields survive during inflation. Such polarizations have been discussed in the Bunch–Davies vacuum. Instead of taking into account the dynamical generation of polarizations of gravitational waves, in this paper, we consider polarized initial states constructed from S U ( 2 ) coherent states. We then evaluate the power spectrums of the primordial gravitational waves in the states.

Sign in / Sign up

Export Citation Format

Share Document