66 research outputs found
A Kerr Metric Solution in Tetrad Theory of Gravitation
Using an axial parallel vector field we obtain two exact solutions of a
vacuum gravitational field equations. One of the exact solutions gives the
Schwarzschild metric while the other gives the Kerr metric. The parallel vector
field of the Kerr solution have an axial symmetry. The exact solution of the
Kerr metric contains two constants of integration, one being the gravitational
mass of the source and the other constant is related to the angular
momentum of the rotating source, when the spin density of the
gravitational source satisfies . The singularity
of the Kerr solution is studied
Isotropic stars in higher-order torsion scalar theories
Two tetrad spaces reproducing spherically symmetric spacetime are applied to
the equations of motion of higher-order torsion theories. Assuming the
existence of conformal Killing vector, two isotropic solutions are derived. We
show that the first solution is not stable while the second one confirms a
stable behavior. We also discuss the construction of the stellar model and show
that one of our solution capable of such construction while the other cannot.
Finally, we discuss the generalized Tolman-Oppenheimer-Volkoff and show that
one of our models has a tendency to equilibrium.Comment: 16 pages Latex, 5 figures, will appear in Adv. High Energy Phys.
(2016
Wormhole solution and Energy in Teleparallel Theory of Gravity
An exact solution is obtained in the tetrad theory of gravitation. This
solution is characterized by two-parameters of spherically symmetric
static Lorentzian wormhole which is obtained as a solution of the equation
with , where .
From this solution which contains an arbitrary function we can generates the
other two solutions obtained before. The associated metric of this spacetime is
a static Lorentzian wormhole and it includes the Schwarzschild black hole, a
family of naked singularity and a disjoint family of Lorentzian wormholes.
Calculate the energy content of this tetrad field using the gravitational
energy-momentum given by M{\o}ller in teleparallel spacetime we find that the
resulting form depends on the arbitrary function and does not depend on the two
parameters and characterize the wormhole. Using the regularized
expression of the gravitational energy-momentum we get the value of energy does
not depend on the arbitrary function.Comment: 11 pages Late
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