"A nice dilemma, we have here. That calls of all our wit..."
http://www.youtube.com/watch?v=qSeBXaaO3qg
The gravity Cartan tetrad 1-form "mobile" LIFs (co-tangent bundle) are the square-roots of the Einstein metric field. They form a homogeneous Lorentz group SO1,3 first rank tensor. Therefore, they are spin 1 4-vector fields like electro-weak-strong fields with a dimensionless coupling that will be renormalizable in quantum gravity if gravity is fundamental and not emergent. This would also naturally explain repulsive dark energy from the VIRTUAL spin 1 gravitons in addition to VIRTUAL spin 0 and the orthodox VIRTUAL spin 2 gravitons all in macro-quantum Glauber coherent states. The vacuum condensates are made of VIRTUAL QUANTA off-mass-shell. Coherent states of on-mass-shell gravitons will be detectable by LISA & LIGO as gravity waves. The virtual coherent states are the non-radiating near gravity fields like the Earth gravity field. One must, however, explain why we find no evidence of spin 1 and spin 0 gravity waves (coherent states of real on-mass-shell gravitons) in binary pulsars.
Steven Weinberg has a very narrow view of all this see his debate with Hehl in Physics Today.
Hehl worked with Yuval Ne'eman.
The Reference Frame: Steven Weinberg vs obsolete physics ideas ...
Mar 3, 2007 ... Steven Weinberg vs obsolete physics ideas: torsion ... between Steven Weinberg and Friedrich Hehl in the new issue of Physics Today. ...
motls.blogspot.com/.../steven-weinberg-vs-weird-physicists.html - Cached - Similar
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Weinberg in Physics Today « Not Even Wrong
Mar 2, 2007 ... It contains a piece by Steven Weinberg based on a banquet talk he .... Hehl had a very influential paper about torsion in Rev Mod Phys in ...
www.math.columbia.edu/~woit/wordpress/?p=529 - Cached
"Gauging the group means that the two parts become arbitrary functions of x. The result,
to put it very roughly, is essentially a manifold which admits local coframes as copies of
the Lorentz group, i.e. the rotational (or homogeneous) part, but which also admits general
coordinate transformations, i.e. the translational part. ... the pseudo-Riemannian metric is a
natural result of the gauging of the translational element of the Poincaré group.23"
GAUGE GRAVITY AND THE UNIFICATION OF NATURAL FORCES
CHUANG LIU