scholarly journals Analytic spectrum of relic gravitational waves modified by neutrino free streaming and dark energy

2007 ◽  
Vol 75 (10) ◽  
Author(s):  
H. X. Miao ◽  
Y. Zhang
Keyword(s):  
Dark Energy ◽  
Gravitational Waves ◽  
Relic Gravitational Waves

scholarly journals RELIC GRAVITATIONAL WAVES AND CMB POLARIZATION IN THE ACCELERATING UNIVERSE

2008 ◽  
Vol 17 (07) ◽  
pp. 1105-1123 ◽  
Author(s):  
Y. ZHANG ◽  
W. ZHAO ◽  
T. Y. XIA ◽  
X. Z. ER ◽  
H. X. MIAO
Keyword(s):  
Dark Energy ◽  
Gravitational Waves ◽  
Accelerating Universe ◽  
Gaussian Functions ◽  
Visibility Function ◽  
Cmb Polarization ◽  
Relic Gravitational Waves ◽  
Physical Elements

In this paper we briefly present our work on relic gravitational waves (RGW) and the CMB polarization in the accelerating universe. The spectrum of RGW has been obtained, showing the influence of dark energy. Compared with those from non-accelerating models, the shape of the spectrum is approximately similar, nevertheless, the amplitude of RGW now acquires a suppressing factor of the ratio of matter over dark energy ∝ Ωm/ΩΛ ~ 0.4 over almost the whole range of frequencies. The RGW Spectrum is then used as the source to calculate the spectra of CMB polarization. By using two half-Gaussian functions as an approximation to the visibility function during the photon decoupling, both the "electric" and "magnetic" spectra have been analytically derived and they are quite close to those obtained numerically. Several physical elements that affect the spectra have been examined, such as the decoupling process, inflation, dark energy, the baryons, etc.

scholarly journals Detecting dark energy fluctuations with gravitational waves

2021 ◽  
Vol 103 (8) ◽  
Author(s):  
Alice Garoffolo ◽  
Marco Raveri ◽  
Alessandra Silvestri ◽  
Gianmassimo Tasinato ◽  
Carmelita Carbone ◽  
...  
Keyword(s):  
Dark Energy ◽  
Gravitational Waves

scholarly journals Gravitational waves: a 100-year tool applied to the dark energy problem

2005 ◽  
Vol 35 (4b) ◽  
pp. 1191-1194 ◽  
Author(s):  
M. Soares-Santos ◽  
S. V. B. Gonçalves ◽  
J. C. Fabris ◽  
E. M. de Gouveia Dal Pino
Keyword(s):  
Dark Energy ◽  
Gravitational Waves ◽  
Energy Problem

scholarly journals The investigation of detectability of the relic gravitational waves based on the WMAP-9 and Planck

2017 ◽  
Vol 26 (02) ◽  
pp. 1750003 ◽  
Author(s):  
Basem Ghayour
Keyword(s):  
Scalar Field ◽  
Gravitational Waves ◽  
Crucial Role ◽  
Planck Data ◽  
Evolution Of The Universe ◽  
Cosmological Observations ◽  
Relic Gravitational Waves ◽  
The Waves ◽  
The Universe ◽  
General Range

The generated relic gravitational waves underwent several stages of evolution of the universe such as inflation and reheating. These stages were affected on the shape of spectrum of the waves. As well known, at the end of inflation, the scalar field [Formula: see text] oscillates quickly around some point where potential [Formula: see text] has a minimum. The end of inflation stage played a crucial role on the further evolution stages of the universe because particles were created and collisions of the created particles were responsible for reheating the universe. There is a general range for the frequency of the spectrum [Formula: see text])[Formula: see text]Hz. It is shown that the reheating temperature can affect on the frequency of the spectrum as well. There is constraint on the temperature from cosmological observations based on WMAP-9 and Planck. Therefore, it is interesting to estimate allowed value of frequencies of the spectrum based on general range of reheating temperature like few MeV [Formula: see text] GeV, WMAP-9 and Planck data then compare the spectrum with sensitivity of future detectors such as LISA, BBO and ultimate-DECIGIO. The obtained results of this comparison give us some more chance for detection of the relic gravitational waves.

scholarly journals SPECTRA OF RELIC GRAVITONS AND BRANS–DICKE THEORY

2005 ◽  
Vol 20 (02) ◽  
pp. 127-134 ◽  
Author(s):  
B. K. SAHOO
Keyword(s):  
Scalar Field ◽  
Energy Density ◽  
Time Dependence ◽  
Gravitational Waves ◽  
Hubble Parameter ◽  
Frequency Dependent ◽  
Cosmological Expansion ◽  
Relic Gravitational Waves ◽  
Matter Energy ◽  
Inflationary Models

The spectra of relic gravitational waves produced as a result of cosmological expansion of the inflationary models are derived in Brans–Dicke (BD) theory of gravity. The time dependence of the very early Hubble parameter and matter energy density are derived from frequency-dependent spectrum of relic gravitational waves. Also it is found that Brans–Dicke scalar field contributes to the energy density of relic gravitons.

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