Behavior of higher modes of gravitational waves and gauge-invariant density perturbations in Bianchi IX cosmological models

1984 ◽  
Vol 286 ◽  
pp. 379 ◽  
Author(s):  
R. J. Slagter
Keyword(s):  
Gravitational Waves ◽  
Cosmological Models ◽  
Invariant Density ◽  
Gauge Invariant ◽  
Higher Modes ◽  
Bianchi Ix ◽  
Density Perturbations

On the Influence of Noise on the Bianchi ix and viii Cosmological Models

1998 ◽  
Vol 9 (11) ◽  
pp. 1813-1825 ◽  
Author(s):  
John Argyris ◽  
Ioannis Andreadis ◽  
Corneliu Ciubotariu
Keyword(s):  
Cosmological Models ◽  
Bianchi Ix ◽  
Influence Of Noise

scholarly journals GENERATION OF SCALE INVARIANT DENSITY PERTURBATIONS IN A CONFORMALLY INVARIANT INERT HIGGS DOUBLET MODEL

2013 ◽  
Vol 28 (19) ◽  
pp. 1350094 ◽  
Author(s):  
MOUMITA DAS ◽  
SUBHENDRA MOHANTY
Keyword(s):  
Scalar Potential ◽  
Higgs Field ◽  
Density Perturbation ◽  
Coupled System ◽  
Higgs Doublet ◽  
Invariant Density ◽  
Scale Invariant ◽  
Conformally Invariant ◽  
Density Perturbations ◽  
Doublet Model

If a Higgs field is conformally coupled to gravity, then it can give rise to the scale invariant density perturbations. We make use of this result in a realistic inert Higgs doublet model, where we have a pair of Higgs doublets conformally coupled to the gravity in the early universe. The perturbation of the inert Higgs is shown to be the scale invariant. This gives rise to the density perturbation observed through CMB by its couplings to the standard model Higgs and the subsequent decay. Loop corrections of this conformally coupled system gives rise to electroweak symmetry breaking. We constrain the couplings of the scalar potential by comparing with the amplitude and spectrum of CMB anisotropy measured by WMAP and this model leads to a prediction for the masses of the lightest Higgs and the other scalars.

scholarly journals Large-scale magnetic fields, non-Gaussianity, and gravitational waves from inflation

2017 ◽  
Vol 32 (36) ◽  
pp. 1747021
Author(s):  
Kazuharu Bamba
Keyword(s):  
Scalar Field ◽  
Magnetic Fields ◽  
Gravitational Waves ◽  
Electromagnetic Fields ◽  
Conformal Invariance ◽  
Large Scale ◽  
Gauge Fields ◽  
Density Perturbations ◽  
Hubble Horizon

We explore the generation of large-scale magnetic fields in the so-called moduli inflation. The hypercharge electromagnetic fields couple to not only a scalar field but also a pseudoscalar one, so that the conformal invariance of the hypercharge electromagnetic fields can be broken. We explicitly analyze the strength of the magnetic fields on the Hubble horizon scale at the present time, the local non-Gaussianity of the curvature perturbations originating from the massive gauge fields, and the tensor-to-scalar ratio of the density perturbations. As a consequence, we find that the local non-Gaussianity and the tensor-to-scalar ratio are compatible with the recent Planck results.

Some exact cosmological models with gravitational waves

1979 ◽  
Vol 72 (4-5) ◽  
pp. 275-276 ◽  
Author(s):  
J. Wainwright ◽  
B.J. Marshman
Keyword(s):  
Gravitational Waves ◽  
Cosmological Models

EVOLUTION OF ISOCURVATURE PERTURBATIONS II: RADIATION-DUST UNIVERSE

1987 ◽  
Vol 02 (02) ◽  
pp. 491-560 ◽  
Author(s):  
HIDEO KODAMA ◽  
MISAO SASAKI
Keyword(s):  
Transfer Functions ◽  
Gauge Invariant ◽  
Component System ◽  
Strongly Coupled ◽  
Analytic Estimate ◽  
Density Perturbations ◽  
Multi Component System ◽  
Characteristic Scales ◽  
Dust Universe ◽  
Isocurvature Perturbations

Density perturbations in a universe in which matter consists of noninteracting nonrelativistic particles(dust) and strongly coupled photon-baryon fluid(radiation) are analyzed in terms of the gauge-invariant formalism extended to a multi-component system. Detailed analytic estimate is presented for the time evolution of both primordially adiabatic and primordially isocurvature perturbations. In particular, analytic formulas for characteristic scales appearing in the transfer functions are derived. The evolutionary behavior of these two types of perturbations are compared and the origins of their differences and similarities are clarified.

scholarly journals Gauge-invariant Hamiltonian dynamics of cylindrical gravitational waves

2003 ◽  
Vol 68 (10) ◽  
Author(s):  
Ioannis Kouletsis ◽  
Petr Hájíček ◽  
Jiří Bičák
Keyword(s):  
Gravitational Waves ◽  
Hamiltonian Dynamics ◽  
Gauge Invariant

scholarly journals Relic gravitational waves in cosmological models based on the modified gravity theories

2021 ◽  
Vol 2081 (1) ◽  
pp. 012002
Author(s):  
I V Fomin ◽  
S V Chervon
Keyword(s):  
Energy Density ◽  
Gravitational Waves ◽  
Modified Gravity ◽  
Direct Detection ◽  
Cosmological Models ◽  
Observational Constraints ◽  
Cosmological Perturbations ◽  
Modified Gravity Theories ◽  
Relic Gravitational Waves ◽  
Gravity Theories

Abstract We consider cosmological models based on the generalized scalar-tensor gravity, which correspond to the observational constraints on the parameters of cosmological perturbations for any model’s parameters. The estimates of the energy density of relic gravitational waves for such a cosmological models were made. The possibility of direct detection of such a gravitational waves using modern and prospective methods was discussed as well.

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