316 research outputs found
Regularization of gravity theories and local Lorentz transformation
We regularized the field equations of gravity theories such that the
effect of Local Lorentz Transformation (LLT), in the case of spherical
symmetry, is removed. A "general tetrad field", with an arbitrary function of
radial coordinate preserving spherical symmetry is provided. We split that
tetrad field into two matrices; the first represents a LLT, which contains an
arbitrary function, the second matrix represents a proper tetrad field which is
a solution to the field equations of gravitational theory, (which are
not invariant under LLT). This "general tetrad field" is then applied to the
regularized field equations of . We show that the effect of the arbitrary
function which is involved in the LLT invariably disappears.Comment: 12 page
On the Regularization of Kerr-NUT spacetime: I
Within the framework of teleparallel equivalent of general relativity (TEGR)
theory, calculation of the total energy and momentum of Kerr-NUT spacetimes
have been employed using two methods of the gravitational energy-momentum,
which is coordinate independent, and the Riemannian connection 1-form,
. It has been shown that the two methods
give the same an unacceptable result, i.e., divergent value. Therefore, a local
Lorentz transformation that plays a role of a regularizing tool, which
subtracts the inertial effects without distorting the true gravitational
contribution, has been suggested. This transformation keeps the resulting
spacetime to be a solution of the equations of motion of TEGR.Comment: 10 pages, Latex (Will appear in Prog. Theor. Phys.
Schwarzschild solution in extended teleparallel gravity
Tetrad field, with two unknown functions of radial coordinate and an angle
which is the polar angle times a function of the redial
coordinate, is applied to the field equation of modified theory of gravity.
Exact vacuum solution is derived whose scalar torsion, , is constant. When the angle coincides with the
polar angle , the derived solution will be a solution only for linear
form of gravitational theory.Comment: 8 pages Late
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