Exploring General Theory of Relativity

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is it possible to get accurate results of general theory of relativity without retaining the concept of four dimensional curved space
 
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sharma_satdev said:
is it possible to get accurate results of general theory of relativity without retaining the concept of four dimensional curved space

GR makes use of Riemannian spacetime and without it, no one is able to obtain Einstein field equations!

AB
 
"Black holes and time warps: Einstein's outrageous legacy" mentions a version of GR that's equivalent to standard GR (in the sense that it makes the same predictions about experiments), but describes spacetime as flat. In this theory, matter doesn't curve spacetime, it deforms measuring devices.

I also think that one of the early attempts at a quantum (field) theory of gravity could accurately reproduce the predictions of GR. (Split the metric into a flat part plus the deviation from flatness, g=η+h, quantize only h, and throw away all Feynman diagrams that contain loops).
 
'Field Theory Gravity' models gravity as a tensor field in Minkowski space. There's a good discussion by Y. Baryshev in arXiv:gr-qc/9912003 v1 (1 Dec 1999). It is generally believed that FTG is identical to GR but Baryshev disputes this and claims they make different predictions in the high-energy regime.
 
In Philippe G. Ciarlet's book 'An introduction to differential geometry', He gives the integrability conditions of the differential equations like this: $$ \partial_{i} F_{lj}=L^p_{ij} F_{lp},\,\,\,F_{ij}(x_0)=F^0_{ij}. $$ The integrability conditions for the existence of a global solution ##F_{lj}## is: $$ R^i_{jkl}\equiv\partial_k L^i_{jl}-\partial_l L^i_{jk}+L^h_{jl} L^i_{hk}-L^h_{jk} L^i_{hl}=0 $$ Then from the equation: $$\nabla_b e_a= \Gamma^c_{ab} e_c$$ Using cartesian basis ## e_I...
Abstract The gravitational-wave signal GW250114 was observed by the two LIGO detectors with a network matched-filter signal-to-noise ratio of 80. The signal was emitted by the coalescence of two black holes with near-equal masses ## m_1=33.6_{-0.8}^{+1.2} M_{⊙} ## and ## m_2=32.2_{-1. 3}^{+0.8} M_{⊙}##, and small spins ##\chi_{1,2}\leq 0.26 ## (90% credibility) and negligible eccentricity ##e⁢\leq 0.03.## Postmerger data excluding the peak region are consistent with the dominant quadrupolar...
Thread 'Dirac's integral for the energy-momentum of the gravitational field'
See Dirac's brief treatment of the energy-momentum pseudo-tensor in the attached picture. Dirac is presumably integrating eq. (31.2) over the 4D "hypercylinder" defined by ##T_1 \le x^0 \le T_2## and ##\mathbf{|x|} \le R##, where ##R## is sufficiently large to include all the matter-energy fields in the system. Then \begin{align} 0 &= \int_V \left[ ({t_\mu}^\nu + T_\mu^\nu)\sqrt{-g}\, \right]_{,\nu} d^4 x = \int_{\partial V} ({t_\mu}^\nu + T_\mu^\nu)\sqrt{-g} \, dS_\nu \nonumber\\ &= \left(...
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