I am confused about the modified theories of gravity. We all know there is the Schwarzschild solution for GR. The solution can give right prediction for the solar-system experiments, such as Light deflection, perihelion shift of the Mercury and gravitational time delay. Whether all kinds of...
CTs are not a change of coordinates but an actual change of the geometry, right? In principle, we can change the Minkowski spacetime into Riemannian one even Riemann-Cartan one by some kind of CT. In the Riemann-Cartan spacetime there is torsion while it is torsion-free for Minkowski spacetime...
Do you mean the fields curve the spacetime? I know in QFT the vacuum is not nothing but with the fields which all reside in the ground states, namely no excitations. So this case it will still have vacuum energy which will curve the spacetime. But you should know at the time of GR's generation...
Rencently, I found myself confused by some fundamental concepts in GR. I hope someone can help me with that.
We all know the vacuum Einstein equation (VEE) without the cosmological constant \Lambda is Rab=0. Since I learn GR the words " matters bend the spacetime " been told again and...
Certainly yes. The interaction between gravitons should give the gravitational energy,which should be contained in the RHS of Einstein field equation. But until now we do not have the satisfactory local definition of gravitational energy-momentum tensor in the frame of Einstein's GR.
In Hehl's paper "general relativity with spin and torsion:Foundations and prospects",there is a sentence ," in the macrophysical limit, mass (or energy-momentum) adds up because of its monopole character, where as spin , being of dipole character, usually averages out." anybody who know the...