General relativity

TL;DR: The notion of wind Finslerian structure is developed in this article, which is a generalization of Finslersian metrics where the indicatrices at the tangent spaces may not contain the zero vector.

TL;DR: In this article, the authors show that light scalar fields can still be studied and constrained through their interaction with photons, and focus particularly on changes to the Cosmic Microwave Background spectral distortions and violations of the distance duality relation.

TL;DR: The Kerr vacuum has two independent invariants derivable from the Riemann tensor without differentiation as discussed by the authors, and these invariants must be examined in order to avoid an erroneous conclusion that the ring singularity of this spacetime is directional.

TL;DR: In this paper, the authors proposed an extension of the Schwarzschild metrics to the 8D symplectic phase manifold, based on Sasaki's metric of the tangent bundle over the pseudo-Riemannian 4D space-time manifold.