In theories of quantum gravity, the graviton is the hypothetical quantum of gravity, an elementary particle that mediates the force of gravity. There is no complete quantum field theory of gravitons due to an outstanding mathematical problem with renormalization in general relativity. In string theory, believed to be a consistent theory of quantum gravity, the graviton is a massless state of a fundamental string.
If it exists, the graviton is expected to be massless because the gravitational force is very long range and appears to propagate at the speed of light. The graviton must be a spin-2 boson because the source of gravitation is the stress–energy tensor, a second-order tensor (compared with electromagnetism's spin-1 photon, the source of which is the four-current, a first-order tensor). Additionally, it can be shown that any massless spin-2 field would give rise to a force indistinguishable from gravitation, because a massless spin-2 field would couple to the stress–energy tensor in the same way that gravitational interactions do. This result suggests that, if a massless spin-2 particle is discovered, it must be the graviton.
As far as I can see, the exchange particle involved in gravitational forces is the graviton. However, in the markscheme for both the original and revised EDEXCEL A-Level Physics PHY3 Topics Paper (topic C) it states that it is the photon.
Which is correct, or are both correct? Why is there this...
The quantum of gravity is called graviton. And using symbols for quanta of length, \psi_E and \psi_B and quanta of linear momentum, \phi_E and \phi_B, the time independent structure of graviton, G^{-} is given by
G^{-} = \psi_E \times \phi_E \cdot \psi_B \times \phi_B
Say a penny is falling to Earth from a height,
Gravitons shoot up from the earth’s surface grabbing the penny and pulling it down to earth.
Fair enough.
Now imagine that directly above that penny is another penny, also falling to earth, the gravitons pulling at this second penny must have...
I'm under the impression that general relativity with it's curved space-time as a description of the gravitational force is commonly accepted in the physics-community.
However there is another interpretation of the gravitational force in terms of a particle, the graviton. This seems to me as...
Does Loop Quantum Gravity support the existence of graviton?
I can't imagine how is it possible that graviton can exist if it is to agree with GR, since GR says that gravity is merely a curvature of spacetime and is isn't a force.
GR => SR => time dilation & length contraction =>> how does...
"Weighing the Graviton"
9^9 (387,420,489) Combinations/Equations
http://physics.nist.gov/cuu/Constants/
[UPDATED 1998 CODATA-NIST VALUES]
The Primary Universal Base Unit Values
1) mass… (hc/G)^1/2 = 5.4563026(39) x 10^-8 kg
2) length… (hG/c^3)^1/2 = 4.0507625(38) x 10^-35 m
3) time…...
Could it be calculated that way?..for example take a gravitational classic wave DHab=0, then by proposing a plane wave solution like that
Hab=AabExp(KaXb) being Aab a tensor we would have the constraint..
AabKaXb=0 or expressed in momentum..AabPaPb=0 (1) so i think it would by proposing a...