All Questions

41 questions
43 views

What happens in theory if we focus gravitational waves into a point?

https://www.youtube.com/watch?v=iWKFPTgkpXo Basically inspired by this video and its comparison with wormholes. While many other questions on the site have already covered the weak strength of ...
64 views

Are GWs made of gravitons (are gravitons the quanta of GWs) or not?

I have read this question: What is the difference between gravitons and gravitational waves? I have read this on wikipedia: However, if gravitons are the quanta of gravitational waves, then ...
24 views

Polarization states of a massive graviton

How could I reconcile the fact that there are 6 polarization states for a gravitational wave (3 transverse and 3 with longitudinal components) with the fact that the spin-2 graviton should allow a ...
13 views

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 ...
220 views

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 ...
97 views

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 ...
25 views

Folded strings or hidden preons as black hole interior: signals with gravitational waves?

Suppose the black hole interior (non-kerr, kerr-like,...) is made of some kind of subsubatomic stuff (e.g., folded strings or superstrings, folded branes, buches of preonic pregeometry or whatever). ...
33 views

Gravitational brehmsstralung

I have read this pdf, and its 5th paragraph, where it talks about gravitational brehmsstralung. https://www.researchgate.net/publication/243311274_Gravitons_in_Minkowski_space-...
5k views

Are we closer to a theory of everything thanks to the detection of gravitational waves?

A couple of weeks ago I heard an astronomer explain that one of the latest detections of gravitational waves was accompanied by simultaneous detections of the same astronomical event in various other ...
39 views

Are Gravitrons still hypothetical? [duplicate]

With the dectection of gravitational waves, can it be assumed that gravity works in the same way as the other fields? If so, isn’t the gravitron a proven part of QFT? Because the wikipedia page says ...
27 views

Quantum gravity and inspirals by emission of gravitational waves [closed]

Should we expect that quantum gravity, just as quantum theory forbids the decay of the fundamental level, avoids the collision of gravitationally bound systems at small scales, despite they emit ...
255 views

What is the relationship between a gravitational wave and a graviton? [duplicate]

Gravitational waves were theorized a century ago and recently discovered, leading to the awarding of the 2017 Nobel Prize in Physics. According to Wikipedia: Gravitational waves transport energy as ...
1k views

Are gravitons real? [duplicate]

Is graviton a particle? What's your view on this? Sence physics is the study of matter, it seems to me forced to believe that the gravitational force are particles. There are no particle called ...
74 views

Consequences of a stable geon

What would be the consequences be of a stable geon? What similiarity, if any, would it have to a naked singularity? What would a stable geon potentially look like, and what would the immediate ...
166 views

What's the relationship between classical gravitational waves and gravitons? [duplicate]

LIGO have detected gravitational waves, why we are still far away from detecting gravitations? how to understand the statement below? A classical wave may be considered to be a coherent ...
133 views

primordial gravitational waves

After reading some literatures Maria Chiara Guzzetti, Nicola Bartolo, Michele Liguori, and Sabino Matarrese. Gravitational waves from inflation. arXiv preprint arXiv:1605.01615, 2016. Andrew R ...
518 views

Could gravitons be quasiparticles like phonons?

The Einstein field equation $$G_{\mu \nu} + \Lambda g_{\mu \nu} = {8 \pi G \over c^4} T_{\mu \nu}$$ basically says: $$\text{curvature of spacetime} \sim \text{stress-energy tensor}$$ The stress-...
148 views

How do I calculate electron acceleration by gravitational waves? [closed]

If the amplitude of gravitational waves, frequency of gravitational waves and the vector potential of magnetic field in surrounding of such waves are known then what would be the easiest way to ...
133 views

Could gravitational waves have a large entropy in quantum gravity?

The question is broad, and we still don't know what is quantum gravity. But let me be more specific. In the question (on this site, see below) on whether gravitational waves have entropy the answers ...
535 views

A spin zero graviton?

Why can the graviton not be a spin 0 particle? On a similar note why can it not be a spin 4, spin 6 particle?
29 views

Why is graviton not found yet? Newton said gravity pulls us, Einstein said space is bent and it pushes us, hawking predicts the existence of graviton and 'hawking radiation'. How far are we from ...
184 views

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 ...
174 views

Is there a path to go from GR, to Gravitational Waves, to Gravitational Particles (Gravitons), to Quantum Gravity?

The articles on the subject often say : a part of the mass of the 2 celestial bodies became energy for gravitational waves after merging : E(gravitational waves) = (M1 + M2 - M_merged).c^2 ...
278 views

What does the finding of gravitational waves mean for M Theory? [duplicate]

I was wondering if the finding of gravitational waves proves M theory. I know at Fermi Lab scientists were looking for gravitons in distant places in our universe so that they can prove string theory. ...
2k views

Prospects for detection of gravitons?

With the announcement of the detection of gravitational waves, questions about the implications proliferate. Some relate to the possible existence of gravitons. The analogous relationship between ...
952 views

Does wave-particle duality exist for gravitational waves?

For electromagnetic waves there exists a wave/particle duality: light sometimes behaves as a wave, and other times as a particle (photons). Does such a duality exist for gravitational waves? In other ...
4k views

Does the existence (now proved) of gravitational waves imply the existence of Gravitons?

I studied the theoretical part about the Gravitational waves in General Relativity (linearization of gravity and small perturbations of the metric and so on). But I was wondering about: since ...
2k views

Evidence for quantum gravity from gravitational waves

The rumor spreads that physicists will make their big gravitational wave announcement this thursday. I am far from being an experimentalist, but I want to know if there is any chance that the ...
252 views

Space-time and gravitational fields

I am reading a book by Carlo Rovelli, Seven Brief Lessons On Physics, and would like to check if I have understood something. Apologies if my question is badly phrased, feel free to edit where ...
76 views

If photons have a wave particle duality would gravitons have a wave particle duality? [duplicate]

If electromagnetic waves are the same as photons would gravitational waves be the same as gravitons?
9k views

What is the difference between gravitons and gravitational waves?

What is the difference between gravitons and gravitational waves? So as I understand, gravitational waves are predicted by and part of the theory of general relativity, whereas gravitons are predicted ...
751 views

Do gravitational waves exist at the quantum level?

Do gravitational waves exist at quantum level produced by electrons or by atoms or by molecules? If yes, which particle produces them and how are they produced? Spacetime exists at a quantum level ...
907 views

Can we create graviton particle or gravitational wave? [duplicate]

Can we create graviton particle or gravitational wave? I want to know if we able to generate graviton particle out of some energy. Is it theoretically possible? And could we generate gravitational ...
215 views

Would the presence of B-modes in the CMB provide evidence for quantum gravity?

Finding B-modes in the CMB (which aren't due to foreground contamination) would be evidence for gravitational waves, because they cannot be produced by density perturbations (to first order, is my ...
508 views

Could future experiments on “Gravitational Casimir Effect” confirm the existence of gravitons?

From Casimir effect, we know that when two plates are placed very close to each other in vacuum, they attract each other because the quantum fluctuations that press on the two plates' outer surfaces ...
393 views

Would a directional “graviton” emitter violate any known laws of physics?

Setting aside that we don't known what the mediating particle in quantum gravity looks like and have no way to manipulate it, what would the implications of a directional graviton source be? Would it ...
3k views

Is the graviton hypothetical?

Wikipedia lists the graviton as a hypothetical particle. I wonder whether graviton is indeed hypothetical or does its existence directly follow from modern physics? Does observation of gravitational ...
276 views

The BICEP2 data are evidence of gravitational waves and of inflation. Are they also the first observation that requires quantum gravity?

It strikes me that the recent announcement of data from BICEP2 contains two really Big Deals: the first evidence of gravitational waves the first evidence of inflation. Is there also a third? the ...
189 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 ...