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7
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126 views

Do photons generate gravitational waves since they affect with their energy the stress tensor?

The gravitational waves are fact. They are produced in a way predicted 100 years before by Einstein. Anything with energy affecting stress tensor of space time produces them. What does it happen with ...
6
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0answers
473 views

Energy-Momentum Tensor of a Gravitational Wave

In radiation gauge ($\gamma=0$), the Einstein field equation in vacuum for a perturbation $\gamma_{\mu\nu}:=g_{\mu\nu}-\eta_{\mu\nu}$ is given by $$ \boxed{ \partial^\alpha\partial_\alpha ...
4
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0answers
52 views

How much energy does the Earth absorb when a gravitational wave passes through it?

I understand that gravitational waves pass quite freely through massive bodies. Quoting http://www.ligo.org/science/GW-Potential.php: Gravitational waves will change astronomy because the universe ...
4
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0answers
123 views

In what shape do gravitational waves radiate?

The recent detection of gravitational waves made me wonder how the amplitude of the waves fell off with distance. My first naive thought was that it was probably by the cube of the distance. ...
4
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0answers
92 views

Can gravitational waves produce “sonic boom”?

I've heard that a fast moving object such as a jet plane traveling much faster than speed of sound can produce shockwaves which is also known as sonic boom, also Cherenkov radiation is produce by ...
4
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0answers
136 views

Will a black hole cause scattering of a gravitational wave?

In my GR textbook, it states that gravitational waves can undergo interference but not scattering. I am just starting the chapter on linearised gravity concepts (weak field approximation) and my ...
4
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0answers
54 views

How do inflationary models predict the generation of gravitational waves during the inflationary period?

Recent results from the BICEP2 experiment have produced a lot of talk about the primordial gravitational waves produced during the inflationary period. I would like to have some explanation about how ...
3
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0answers
101 views

Do gravitational waves propagate backwards in time?

Gravitational waves are spacetime waves, which stretch and squeeze both space and time. Since relativity puts space and time (almost) on an equal footing, it seems to me that since gravitational waves ...
3
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0answers
35 views

Is there high ring-down frequencies in LIGO's recent discovery?

This question is from Physics overflow: question in physicsoverflow. I am reading LIGO's new discovery of gravitational waves by black hole merger. During the merger, two phases are not hard to ...
3
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0answers
84 views

Gravity vs Gravitational Waves

I thought I had a reasonable understanding of relativity, the speed of light speed limit, and how this stuff related to gravity. Then I read through all the answers/comments for this question: How ...
3
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0answers
42 views

Can gravitational waves observed far from a black hole tell us anything about the multipole moments of a dynamical horizon?

In a paper by Ashtekar et al in 2013 on the approach to the final state to a stationary black hole they study the evolution of the multipole moments of dynamical horizons, which relax away (except for ...
3
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0answers
44 views

Do gravitational vawes deplete energy even if there's nothing they can affect?

I've read multiple times that one of consequences of gravitational waves being a thing is, that they make any orbit unstable. As long as the two or bodies orbit around each other, they create ...
3
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0answers
94 views

Momentum transfer from gravitational wave

There has been some discussion here of the magnitude of the tidal distortion caused by a wave of the type reported on Feb. 11 2015, with the conclusion being that a tidal (distortion) effect ...
3
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0answers
67 views

Maximum Power transmitted using General Relativity waves - cf Schwinger limit

In Electromagnetism, QED says that the linearity of Maxwell's equations comes to an end when field strengths approach the Schwinger limit. Its about 10^18 V/m. What is the corresponding formula for ...
3
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0answers
147 views

Computing linearized gravitational wave emission from point-like masses

I'm trying to compute the gravitational wavefront created from a set of moving masses. I'm trying to apply the equation $$ h_{jk} = \frac{2}{r} \frac{d^2 Q_{jk}}{dt^2}$$ Where $h$ is the linearized ...
3
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0answers
177 views

What does BICEP2's results tell us about gravitation waves and quantum gravity?

The BICEP2 results, unless I am mistaken, are a measurement of CMB polarization, i.e. photon polarization. That is, taken at face value they say nothing about gravity directly. Now, we can start to ...
2
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0answers
27 views

Gravitational waves: simulations of signal

I am self-learning GR. I was wondering if there is any open source software to help learn more about the signal processing of gravitational waves. E.g. a software that injects a signal into random ...
2
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0answers
74 views

Non-locality of gravitational energy

Gravitational energy is non-local which is essentially because of the equivalence principle. The equivalence principle says that you can always transform your frame so that you feel like in a ...
2
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0answers
47 views

Have gravitational waves any effect on the electromagnetic waves in interferometers?

I am not into general relativity, but the explanation of how an interferometric gravitational antenna works is generally pretty basic. In the recently published paper announcing the detection of ...
2
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97 views

Can a gravitational wave produce oscillating time dilation?

I was reading about gravitational waves and about laser based detectors. I also read this. As mentioned in the answer, when ever there is a deformation in spacetime, doesn't it also create a minute ...
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0answers
24 views

Why '1+log slicing condition' and 'Gamma Driver Shift Condition' were successful in black hole simulations?

The 1+log slicing and Gamma driver shift conditions are I want to know if there is a specific reason why these conditions were used most for Black Hole simulations in Numerical Relativty. And how ...
1
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0answers
42 views

Can Bose-Einstein Condensates reflect gravitational waves?

This is a question based on the paper by Raymond Chiao in 2002 where it is stated: One of the conceptual tensions between quantum mechanics (QM) and general relativity (GR) arises from the clash ...
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0answers
48 views

Using geodesic deviation for freely falling particles when gravitational waves comes through

Suppose we have a gravitational wave which gives us the following metric $$ds^2=-dt^2+(1+h_+\cos(\omega(t-z)))dx^2+(1-h_+\cos(\omega(t-z)))dy^2+dz^2$$ I want to calculate the time it takes for a ...
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0answers
55 views

LIGO detection statistic, SNR formula

According to B. P. Abbott paper published in Physical Review Letters, "Observation of Gravitational Waves from a Binary Black Hole Merger" ...
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0answers
62 views

Gravitational Waves + impedance

Why isn't there an Impedance with gravitational waves? http://www.scientificamerican.com/video/gravitational-waves-are-the-ringing-of-spacetime/
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46 views

Do gravitational waves produce real accelerations?

Do gravitational waves produce real accelerations? For example, if I have an electron and a gravitational wave passes by, will the electron emit electromagnetic waves according for instance to Larmor ...
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0answers
18 views

Higher dimensional trapped surface and its condition?

In higher D-dimensional spacetime, a marginally trapped surface is a closed spacelike (D-2)-surface whose outer null normals have zero convergence. It is very like a marginally trapped surface in the ...
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0answers
58 views

Differential precession due to gravitational waves

To motivate the question, Andy Strominger recently put out a paper on calculating the Sagnac shift of counterrotating beams due to the angular momentum flux of a passing gravitational wave. See ...
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0answers
67 views

Colliding black holes to an outside observer

We know that a particle approaching an event horizon will appear to an outside observer to slow down and never cross the horizon. What is observed by an outside observer when a singularity ...
1
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0answers
96 views

One more time about the connection of Weyl tensor and gravitational waves

There is differential identity with Weyl tensor and energy-momentum tensor: $$ D^{\lambda}C_{\lambda \alpha \sigma \beta} = 4 \pi G \left(D_{\sigma}T_{\alpha \beta} - D_{\beta}T_{\alpha \sigma} + ...
0
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0answers
24 views

Gravitational waves' Amplitude

Gravitational waves are disturbances in gravitational field which in turn is the curvature of space-time. So my question is it possible to somehow measure the amplitude of a gravitational wave and if ...
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0answers
30 views

How does one derive Christodoulou Memory Effect?

There is a non-linear effect associated to the permanent displacement of test masses when a gravitational wave interact with them. This is called the Christodoulou memory effect. How does one obtain ...
0
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0answers
26 views

Non equilibrium black hole radiating away energy and angular momentum, with total energy and angular momentum conserved

The question refers to whether mass (i.e., energy) and angular momentum can be considered to have been carried away by the gravitational radiation in the hole settling down. And whether those entities ...
0
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0answers
23 views

shouldn't a photon traversing the vacuum always be associated with a gravitational wave?

In perusing the linearized Einstein equation, it appears that even a classical electromagnetic plane wave would always have to be associated with a tensor perturbation to the background spacetime. ...
0
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0answers
68 views

What is the explicit form of $\tau^{\alpha\beta}$ in the linearized Einstein field equations $\Box h^{\alpha\beta}=-16\pi\tau^{\alpha\beta}$?

If we let $h^{\alpha\beta}=\eta^{\alpha\beta}-g^{\alpha\beta}\sqrt{|det(g)|}$ then, according to wikipedia, the Einstein Field Equations become $$\Box h^{\alpha\beta}=-16\pi\tau^{\alpha\beta},$$ where ...
0
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0answers
108 views

Did the LIGO measure gravitomagnetic waves as well?

I think of gravitomagnetism as as the "magnetic" portion of gravity, with gravity being the "electric" portion. Since gravity ("electric") seems to affect space (which the LIGO could detect) what ...
0
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0answers
36 views

Does the gravitational wave community plan to lower the threshold for claiming detections by 2000x?

I've read: To investigate the impact of reducing the parameter space for GRB searches, we will deliberately avoid the question of first gravitational wave detection - where a "5-sigma" ...
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0answers
64 views

Which formula was used to get Gravitational Waves animation?

I would like to make animation like this by myself It is from wikipedia article "Gravitational wave". But if I use formula from wikipedia article "Gravitational wave" subsection "7.2.2 Wave ...
0
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0answers
61 views

Do gravitational waves have field components like electromagnetic waves?

One way I've been led to understand electromagnetic waves (and I accept that this might be a misconception I have) is that they 'self propagate' through empty space by virtue of the wave consisting of ...
0
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0answers
55 views

If we were orbiting the two black holes that LIGO detected, would anyone notice?

The two black holes that merged released an ENORMOUS amount of gravitational energy. According to National Geographic this was: In the last second before the black holes merged, they released 50 ...
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44 views

Gravitational waves parallel

Just an idea to illustrate the gravitational waves. This kind of analogy is proposed: When you have a rotational motion of the fluid, some small amount of the energy is radiated as a pressure ...
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0answers
23 views

Numerical simulation of strong field gravitational vacuum solutions colliding

I am interested in the current state of knowledge of strong field General Relativity learned from numerical investigations of gravitational wave packets colliding with each other or black holes. If ...
0
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0answers
89 views

How much time distortion was caused by GW150914?

I understand (at least I think I understand) that LIGO used distortion of space to detect GW150914 (one arm grew longer, the other arm grew shorter, causing interference in the returning laser-pulse ...
0
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0answers
38 views

Do gravitational waves interact with the Earth's magnetic field?

Do gravitational waves cause a minor vibration of the Earth's magnetic field, and therefore a minor (if undetectable) electrical inductance?
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0answers
58 views

How do gravitational waves and black holes interact?

Following the first detection of gravitational waves yesterday (11 Feb. 2016) by LIGO, I have a couple of questions about how gravitational waves and black holes interact. Assume that there is a ...
0
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0answers
44 views

General relativity degrees of freedom — simplified version?

I'm afraid my question may be too general, but I would like to ask how I could find out the degrees of freedom in a given tensor. I have had this question since I started studying GR. At first, I ...
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0answers
62 views

Evidence of possible tidal effects close to a gravitational wave emitting system

Currently we are attempting to detect gravitational wave emissions using the LIGO gravitational wave detection system (and similiar systems), by attempting to detect very weak gravitational waves ...
0
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0answers
43 views

Is it true that GR waves can interfere if and only if the change to the metric can take negative values?

This appears to be a unique question compared to other topics about electromagnetic waves or quantum mechanics already on Stack Exchange. The topic on resonance doesn't really answer this question. ...
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0answers
18 views

objects and particles react to wave

Is it possible for a wave to be have a wavelength so small that it doesn't interact/affect an object? Like if it is smaller than the atoms itself will it still affect them? I am talking about a wave ...
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0answers
65 views

Generalized long wave and KdV equation

I have read many papers about benjamin-bona-mahony (BBM) equation or Regularized Long Wave (RLW) equation and found that BBM equation can be derived from KdV equation. from other papers i got others ...