All Questions
Tagged with cosmology gravitational-waves
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The data file of the LISA Interferometer results
How to extract the data of the strain versus frequency plot of the Laser Interferometer Space Antenna (LISA): Figure (2) in this paper:
https://arxiv.org/abs/1702.00786
The paper doesn't contain any ...
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How to plot the curve of the gravitational wave energy density giving the data of the strain versus frequency
I want to plot the curve of energy density ($\Omega$) of the gravitational waves versus frequency that are predicted by the Einstein telescope. But in the ET pages:
https://moscow.sci-hub.se/4444/...
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If gravitons are 'real' and analogous to photons are they also being 'stretched' by the universe's expansion?
Since photon wavelengths are stretched by our expanding universe, appearing to us as a redshift, would graviton wavelengths similarly be stretched? For that matter, do gravitons even have a ...
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Can either of LISA, NanoGrav or LIGO measure the polarization of gravitational wave background (GWB)?
Polarization in GWB should carry as much important information as in CMB. However, I've done some superfluous literature research and found little discussion. Is there any planned project for ...
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Which is the total energy density constraint for the gravitational wave background?
Different constraints from different measuring methods have been set on different frequency ranges of the energy density of gravitational waves, as shown in the picture below. What is the total energy ...
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Thermal models of gravitational radiation?
How is the background noise of gravitational waves modeled? Is it a thermal model, giving a stochastic distribution of the curvature tensor (field-strength tensor) in ambient space? That is, every ...
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Gravitons in a vacuum
I'm new so please be nice if I don't know too much about anything.
I was kind of curious about the idea of gravitons in a vacuum. (using string theory, or even superstring theory.) if space is a near-...
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Number of gravitational wave events needed to calculate Hubble parameter
How many GW events do we need to measure the Hubble parameter with a precision 1-5%? How do we calculate that number?
- 12.5k
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How much uncertainty has the relic graviton background?
In the paper [1], it is mentioned that inflation predicts that a relic graviton background is about 0.9 K (cf. cosmic neutrino background, 1.945 K, and cosmic microwave background, 2.73 K). How much ...
CommunityBot
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Can gravitational waves gain energy in an expanding FRW spacetime?
I was reading this paper (Green's functions for gravitational waves in FRW spacetimes: https://arxiv.org/abs/gr-qc/9309025) I had a specific question about one statement in the paper that I would like ...
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Faster-than-light gravitational waves and faster-than-light expansion in the inflation
I have no introduction to the inflationary epoch. I know, however, that during this time space-time expanded with a speed faster than the speed of light. If gravitational waves are perturbations of ...
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*Observational* Consequences of Energy Nonconservation in GR
What are the experimental or rather observable consequences of the non-conservation (or conservation) of energy in GR? Imagine our instruments were $10^3$ or even $10^6$ more sensitive, better ...
- 39k
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Cosmological consequences of the mass-energy content of gravitational waves
This paper published in 1969 indicates that a majority of the mass-energy of the universe may be contained in gravitational waves:
"Turning next to phenomena on a galactic scale, we find it ...
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Could gravitational waves be cosmologicaly 'redshifted'? [duplicate]
Is it posible that gravitational waves detected here on Earth could be cosmologicaly 'redshifted'? So, at emission they had higher frequency then after reaching Earth?
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LIGO et al: Is it possible to estimate the frequency of GW+EM detections?
In the past few years LIGO and VIRGO have detected a multitude of gravitational events. As far as I know however only GW170817 had a verifiable EM counterpart. Shouldn't it be possible, based on ...
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