Bianchi cosmologies, magnetic fields, and singularities

Future of Bianchi I magnetic cosmologies with kinetic matter

“…We have considered small solutions to the Einstein-Vlasov system with Bianchi I symmetry and a pure magnetic field because Bianchi I magnetic space-times are of physical interest and might help to solve the Hubble tension [1,7,10,13]. We have shown that these solutions have a dust-like behaviour at late times and have obtained the decay rates of the main variables involved generalising [25].…”

“…Equation ( 1) is the Einstein equation where G αβ is the Einstein tensor which is equal to the energy momentum tensor T αβ which is split into the part coming from the matter described by kinetic theory T Vl αβ and the part coming from the Maxwell field strength F αβ which gives rise to T M αβ . From (7) we can see that T M αβ is trace-free. Equations ( 2) and ( 3) are the Maxwell equations for the Maxwell field tensor F αβ without sources, so in particular we are considering that the particles are not charged.…”

Kantowski–Sachs Model with a Running Cosmological Constant and Radiation

“…This metric has only two conformal factors and enables one to explore the main qualitative features of the anisotropic running cosmology in the most economic and explicit way. It is worth noting that isotropization in the KS cosmological models without running was previously explored in many papers, including [20][21][22], where the isotropization of the metric was first discovered (see also [23][24][25][26][27][28][29][30][31] for further investigations in different models and [32,33] for a more complete set of references). It is worth noting the quantum mechanism of isotropization (see, e.g., [34][35][36]; there are also many other papers on this issue and a review in the book [37]).…”