2021/05/12 by Rolando Gaitán, Gaitan, Rolando, Yessica Dominguez +1
Earth and Planetary Sciences · Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Physics - Theory (hep-th)
paper · pdf · doi:10.48550/arxiv.2105.05666
openalex publication_date 2021/05/12 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
Some classical aspects of Metric-Affine Gravity are reviewed in the context\nof the F(n)(R) type models (polynomials of degree n in the Riemann\ntensor) and the topologically massive gravity. At the non-perturbative level,\nwe explore the consistency of the field equations when the F(n)(R) models\nare reduced to a Riemann-Christoffel (RCh) space-time, either via a\nRiemann-Cartan (RC) space or via an Einstein-Weyl (EW) space. It is well known\nfor the case F(1)(R)=R that any path or reduction "classes" via RC or EW,\nleads to the same field equations with the exception of the F(n)(R)\ntheories for n>1. We verify that this discrepancy can be solved by imposing\nnon-metricity and torsion constraints. In particular, we explore the case\nF(2)(R) for the interest in expected physical solutions as those of\nconformally flat class. On the other hand, the symmetries of the topologically\nmassive gravity are reviewed, as the physical content in RC and EW scenarios.\nThe appearance of a non-linearly modified selfdual model in RC and existence of\nmany non-unitary degrees of freedom in EW with the suggestion of a modified\nmodel for a massive gravity which cure the unphysical propagations, shall be\ndiscussed.\n