33 research outputs found
Axially symmetric stars in Einstein-Maxwell theory
In this work we show how to construct general relativistic star models with
axial symmetry in the Einstein-Maxwell theory. Starting with a general axially
symmetric interior fluid solution we show how to construct the corresponding
electrically charged and also the corresponding magnetized solution of the
Einstein-Maxwell-fluid equations. As an example, we provide an electrically
charged version of the anisotropic Bower and Liang solution.Comment: 9 pages, no figures. v2. corrected an incorrect statement in section
2.1. Updated list of references. arXiv admin note: text overlap with
arXiv:1804.0807
A Toy Model Approach to the Canonical Non-perturbative Quantization of the Spatially Flat Robertson-Walker Spacetimes with Cosmological Constant
We present a toy model approach to the canonical non-perturbative
quantization of the spatially-flat Robertson-Walker Universes with cosmological
constant, based on the fact that such models are exactly solvable within the
framework of a simple Lagrangian formulation. The essential quantum dynamical
metric-field and the corresponding Hamiltonian, explicitly derived in terms of
annihilation and creation operators, point out that the Wheeler - DeWitt
equation is a natural (quantum) generalization of the - Einstein
equation for the classical De Sitter spacetime and selects the physical states
of the quantum De Sitter Universe. As a result of the exponential universal
expansion, the usual Fock states (defined as the eigenstates of the
number-operator) are no longer invariant under the derived Hamiltonian. They
exhibit quantum fluctuation of the energy and of the metric field which lead to
a (geometrical) volume quantization.Comment: 22 pages, LaTe