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Questions tagged [gravitational-waves]

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Do gravitational waves violate the information paradox?

I know when black holes collide, the remnant black hole has a lower mass than the sum of the original two masses. This is due to energy loss via gravitational wave emission. Does this violate the ...
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What comes out of binary black holes at end of inspiral?

When 2 blackholes are orbiting each other so close that they lose more energy in form of gravitational wave, this process is inspiral and is unstoppable until it explodes. This is an extremely violent ...
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Does dark matter need a second force to collect in ordinary matter?

Some experiments search for dark matter interactions at the center of bodies like the Sun and Earth, assuming that if there is some interaction with ordinary matter that allows dark matter to lose ...
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Is there any way gravitons can be found in gravitational waves? [duplicate]

I've been thinking for the past week about this thing, maybe due to my poor understanding of GR... So, if we try to measure the speed of a gravitational wave (I don't know if it's possible yet), and ...
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1answer
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Why do external observers see LIGO results if an object falling into a black hole never reaches the event horizon? [duplicate]

If I throw a clock towards a black hole, its time slows down, it is redshifted, and according to many theories it never reaches the event horizon from my point of view. How is it then, that a star can ...
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Now when we can measure gravitational field, how does the principle of equivalence hold true?

LIGO measured gravitational field waves. The whole thought experiment of Einstein, leading to ‘principle of equivalence’, assumes that there is no way to know inside the rocket that whether its ...
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1answer
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Do gravitational waves affect the flow rate of time?

Since LIGO has been able to detect the presence of gravitational waves, this implies that there is a density wave traveling through space with a high potential front and a low potential back side. ...
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1answer
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Electric quadrupole radiation and supernova core collapse

I have a question when I'm learning the electric quadrupole radiation in E&M. In the radiation zone, the vector potential $\vec{A}(\vec{r},t)$ generated by the current distribution $\vec{J}(\vec{r}...
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Gravitational waves and chirp waveform

When two neutron stars collide emitting gravitational waves, what exactly does the chirp waveform represent and how is it used to infer the distance to the source?
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Could gravitational waves give an illusion of an expanding universe? [closed]

‪Could the effect of “expanding” gravity (gravitational waves spreading at the speed of light) as it travels through space (and therefore becomes less local) red-shift all EM waves and thus give us ...
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Speed of gravitational wave in strong gravity

I have a question about gravitational waves which I can't really find an answer to. My current understanding is that one assumes there is some frame in which the metric has the form $g_{\mu\nu} = \...
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Two black holes merging in our Milky way: GW signal strength?

Gravitational waves detected recently by LIGO interferometers were generated at very large distances, e.g. 440 MegaParsec for GW151226. Would Joseph Weber be able to detect such event with his ...
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Are there any time-periodic solutions to Einstein's equations apart from black holes?

Are there any solutions to Einstein's equations which are periodic in time? A black hole only has mass, charge and angular momentum according to the no-hair theorem. (Although this might just mean in ...
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Gravitational waves interference lensing

Is it possible to detect gravitational waves interference pattern in space, using a telescopes alone or a telescope coupled by gravitational lensing?
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Can the vibrations from the Earth affect gravitational wave detectors?

I was very interested in gravitational wave detectors and how they work exactly. From what I know they set up two lasers with mirrors set up to cancel each other out. Then if movement is detected from ...
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On what timescale does gravitational wave emission circularise an orbit?

Gravitational waves remove both energy and angular momentum from a binary orbit. Both rates are enhanced in non-circular (eccentric) orbits and I presume that (like tidal friction) the net effect will ...
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Significance of the LIGO experiment with respect to length contraction

it might be best to first detail my (admittedly limited) understanding of the LIGO experiment. a beam of light is split along two 4Km evacuated pipes then reflected back where their interference ...
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Could a black hole and a white hole cause gravitational waves, if orbiting one another?

I have been puzzled by an idea that I came across while reading about white holes. But I've only just started learning about white holes, so my knowledge is severely limited. It seems I also can't ...
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1answer
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Two black holes colliding (classical mechanics)

I had this question come up in my exam where two identical black holes are in orbit around each other. There is a loss of energy via gravitational waves : $$\frac{d E}{d t} = kr^4\omega^6$$ where $k$ ...
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Energy of an event for a human observer at a distance of 1 astronomical unit to physically feel the gravitational waves using inverse square law?

I'm asking this question to satisfy my curiosity about how much energy (in joules) it would take for a human astronaut to feel a gravitational wave from a distance of 1 astronomical unit (AU) from two ...
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1answer
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Gravitational wave behavior [duplicate]

My guestion is since we have now detected gravitational waves can gravitational waves go through interference (ie destructive or constructive interference) with each other like other waves?
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Propagation of gravitaional waves near black holes [duplicate]

As we know near black holes light gets strongly deflected. And if the gravity of the black hole is strong enough, the light can move in circles around the black hole. How the gravitational wave ...
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1answer
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How can gravitational waves from such a long distance affect the beam of light?

Even if it does affect it should affect all the surrounding object making it impossible to detect any change. It would be like keeping a man and a scale in a room, and if a gravitational wave is ...
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1answer
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Do mass and motion affect space-time differently?

Mass is said to create curvatures in space-time thereby creating gravity, yet technically the smallest movements, even on Earth, create gravitational waves. Are there different "types" of disturbances ...
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Bound on large extra dimensions using gravitational waves

Are there proposed observations using gravitational waves which put a bound on the size of large extra dimensions (say in the context of ADD model)? The claim in the ADD paper is that you cannot ...
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Would a free falling object hits by gravitational wave accelerate towards the source however briefly?

Gravity is acceleration so I would imagine an object that is in free fall to experience a force when hits by the gravitational wave but in which direction is my question?
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Could gravitational wave permanently distort a region of space time?

Imagine a flat spacetime being disturbed by a gravitational wave from a very distant source, say given enough time would that flat spacetime recovers meaning it must be at the same state as before, ...
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Why does spacetime propagate gravitational waves?

Setting the scene: If I drop a stone into water, the stone will create a depression in the water that the surface tension of the water and gravity (so says the Wiki article: Dispersion (water waves)) ...
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Does a non-wobbling rotating black hole produce gravitational waves if it were to suddenly accelerate its rotation?

My understanding is anything that have mass and accelerate produce gravitational wave however small, suppose I have a rotating black hole and nothing orbits it and it's spin suddenly accelerates. Does ...
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1answer
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Where do gravitational waves and general relativity coincide? [closed]

In the first ten seconds of this video (https://www.youtube.com/watch?v=iphcyNWFD10) the host says that gravitational waves were the result of two black holes merging. That would seem like there is ...
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1answer
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Does LIGO accounts for Sagnac effect?

After reading Sagnac effect one thing immediately come to my mind is LIGO, I only read that the team building LIGO have already considered the curvation of Earth surface but what about Earth's ...
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Can gravitational lensing also applied to gravitational wave?

We know light travels in a straight line but spacetime around an object with mass is curved, anyhow I'm wondering gravitational wave going at speed of light could also be bended by stars and probably ...
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1answer
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Can higgs field ripples like gravitational wave?

Gravitational wave are produced when 2 massive objects orbit each other at high speed or collide, how about higgs field? can it ripples and what sort of event can cause it to ripple?
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Are the masses of merging black holes correlated?

LIGO/VIRGO recently released data on observed "gravitational wave transients", mostly BH-BH mergers. The data includes a plot of the primary and secondary mass (the primary mass is defined as the ...
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Do gravitational wave produce varying electromagnetic waves? [closed]

When gravitational waves produce electromagnetic waves, do they produce them of the same frequency or of varying wavelength?
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How to interpret results of stationary phase approximation in GW case?

As time increases, the amplitude and frequency of the GW signal also increase. But after using the stationary phase approximation, the signal is proportional to ${1/f^{7/6}}$, where $f$ is the GW ...
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1answer
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How are sound waves and gravitational waves different?

What is the difference between sound waves and gravitational waves? The source term in GR as I understand it is the energy-momentum tensor which contains pressure, which makes me think sound is a ...
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2answers
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What is the shape of a gravitational wave form?

What is the shape of a gravitational wave as it hits the Earth, particularly the time portion. Does time start at normal speed, then slow slightly, and then return to normal speed? Or does it start ...
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How do gravitational waves agree with Lorentz invariance?

Following is a simple but incorrect explanation for gravitational waves. My question is what is wrong with it? I'd like to say that a gravitational wave is a periodic variation in the local ...
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Gauge invariance of pseudo stress-energy tensor of gravitational waves

The pseudo stress-energy tensor of gravitational waves is given by $$T_{\mu\nu}^{(\mathrm{G}\mathrm{W})} = \frac{1}{32\pi}\left\langle \partial_{\mu} \bar{h}_{\alpha\beta} \partial_{\nu}\bar{h}^{\...
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Can LIGO be explained in terms of gravitons?

If electromagnetic waves from a star are so faint, all that can be detected are single photons on a photographic plate. For the LIGO experiment, the gravitational waves were so weak, I would have ...
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Why do numerical relativity papers show $\ddot{h}_x$ instead of $h_x$ for gravitational waves amplitude?

I am very confused about why numerical relativity papers, when talking about gravitational wave extraction, usually plot the real part of the fourth Weyl scalar, $\Psi_4$, instead of its double ...
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Gravitational refraction

I recently used another venue to ask about the speed of gravity, specifically if the speed of gravity is constant or if it is subject to refraction when passing through media, akin to light. The ...
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1answer
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Does linear memory effect encode in the gravitational waves?

I read from a few papers that the gravitational memory effect has linear and nonlinear parts: $$\Delta h^{TT}=\Delta h^{TT}_{linear}+\Delta h^{TT}_{nonlinear}$$ and the nonlinear part is encoded in ...
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1answer
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Constructing Gravitational waves with gravitons

Suppose I want to construct a gravitational wave as a coherent sum of many gravitons. It's easy to think of what the frequency distribution of the gravitons should be, as all the LIGO discoveries more ...
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1answer
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What is the interaction of gravitational waves?

Please excuse my lack of knowledge about the subject but, If gravitational waves travel thru the fabric of space time do they interact with each other? Meaning do they create interference patterns ...
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Would pilot-wave gravity reconcile Bohmian mechanics with relativity? [closed]

I was reading Can Bohmian mechanics be made relativistic? from 2016 that attempts to reconcile Bohmian mechanics with relativity. It’s conclusion says: Is such a theory then fundamentally—and/or ...
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Is a GASER a theoretical possibility? [closed]

This question (basically an analogy ) is inspired by several questions and answers that appeared on stackexchange.  We first define GASER, for the purpose of this question. GASER - gravitational (...
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What is the upper bound for the index of refraction of space?

It seems that gravitational waves and gamma waves travail at about the same speed, arriving within seconds of each other over distances in the ranges of $10^6$LY. Naively, I would assume this caps the ...
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Why does the LIGO observation disprove higher dimensions?

I recently read this article which claims that last year’s LIGO observation of gravitational waves is proof that, at least on massive scales, there cannot be more than three spatial dimensions. I ...