arXiv subjects

Prasanta Mahato

Publications and source records attributed to Prasanta Mahato.

11 recordsLinked to original sources

arXiv2012

Axial Current and Noether Charge

A decade ago, a Lagrangian density has been proposed by the author where only the local symmetries of the Lorentz subgroup of (A)ds group is retained. This formalism has been found to produce some results encompassing that of standard Einstein-Hilbert formalism. In the present article, the conserved axial vector matter currents, constructed in some earlier paper, have been found to be a result of Noether's theorem. PACS: 04.20.Fy, 04.20.Cv, 11.40.-q Keywords: Torsion, Axial Current, Noether's Theorem

gr-qc↗

arXiv2012

Multiplicative Torsion and Axial Noether Charge

Some times ago, a Lagrangian density has been proposed by the author where only the local symmetries of the Lorentz subgroup of (A)ds group is retained. This formalism has been found to produce some results encompassing that of standard Einstein-Hilbert formalism. In the present article, the conserved axial vector matter currents, constructed in some earlier paper, have been found to be a result of Noether's theorem.

gr-qc↗

arXiv2011

Axial Current, Killing Vector and Newtonian Gravity

Starting from the multiplicative torsion approach of gravity and assuming a Killing vector to be proportional to the axial-vector matter current, here we derive Newton's law of gravity where the logarithm of the proportionality factor has been found to be the potential function.

gr-qc↗

arXiv2011

Torsion, Chern-Simons Term and Diffeomorphism Invariance

In the $torsion \otimes curvature$ approach of gravity Chern-Simons modification has been considered here. It has been found that Chern-Simons contribution to the bianchi identity has become cancelled from that of the scalar field part. But "homogeneity and isotropy" consideration of present day cosmology is a consequence of the "strong equivalence principle" and vice-versa.

gr-qc↗

arXiv2008

Torsion and Axial Current

The role of torsion and a scalar field $ϕ$ in gravitation, especially, in the presence of a Dirac field in the background of a particular class of the Riemann-Cartan geometry is considered here. Recently, a Lagrangian density with Lagrange multipliers has been proposed by the author which has been obtained by picking some particular terms from the SO(4,1) Pontryagin density, where the scalar field $ϕ$ causes the de Sitter connection to have the proper dimension of a gauge field. In this formalism, conserved axial vector matter current can be constructed, irrespective of any gauge choice, in any manifold having arbitrary background geometry. This current is not a Noether current.

gr-qc↗

arXiv2008

Torsion, Scalar Field and f(\mathcal{R}) Gravity

The role of torsion and a scalar field $ϕ$ in gravitation in the background of a particular class of the Riemann-Cartan geometry is considered here. Some times ago, a Lagrangian density with Lagrange multipliers has been proposed by the author which has been obtained by picking some particular terms from the SO(4,1) Pontryagin density, where the scalar field $ϕ$ causes the de Sitter connection to have the proper dimension of a gauge field. Here it has been shown that the divergence of the axial torsion gives the Newton's constant and the scalar field becomes a function of the Ricci scalar $\mathcal{R}$. The starting Lagrangian then reduces to a Lagrangian representing the metric $f(\mathcal{R})$ gravity theory.

astro-ph↗

arXiv2006

$θ$-Term and Cosmological Constant from CJD Action

In the gravity without metric formalism of Capovilla, Jacobson and Dell, the topological $θ$-term appears through a canonical transformation.The origin of this canonical transformation is probed here. It is shown here that when $θ$-term appears cosmological $λ$-term also appears simultaneously.

gr-qc↗

arXiv2006

Gravitational Constant and Torsion

Riemann-Cartan space time $U_{4}$ is considered here. It has been shown that when we link topological Nieh-Yan density with the gravitational constant then we get Einstein-Hilbert Lagrangian as a consequence.

gr-qc↗

arXiv2006

Torsion, Dirac Field, Dark Matter and Dark Radiation

The role of torsion and a scalar field $ϕ$ in gravitation, especially, in the presence of a Dirac field in the background of a particular class of the Riemann-Cartan geometry is considered here. Recently, a Lagrangian density with Lagrange multipliers has been proposed by the author which has been obtained by picking some particular terms from the SO(4,1) Pontryagin density, where the scalar field $ϕ$ causes the de Sitter connection to have the proper dimension of a gauge field. In this article the scalar field has been linked to the dimension of the Dirac field. Here we get the field equations for the Dirac field and the scalar field in such a way that both of them appear to be mutually non-interacting. In this scenario the scalar field appears to be a natural candidate for the dark matter and the dark radiation.

gr-qc↗

arXiv2006

Torsion, Scalar Field, Mass and FRW Cosmology

In the Einstein-Cartan space $U_4$, an axial vector torsion together with a scalar field connected to a local scale factor have been considered. By combining two particular terms from the SO(4,1) Pontryagin density and then modifying it in a SO(3,1) invariant way, we get a Lagrangian density with Lagrange multipliers. Then under FRW-cosmological background, where the scalar field is connected to the source of gravitation, the Euler-Lagrange equations ultimately give the constancy of the gravitational constant together with only three kinds of energy densities representing mass, radiation and cosmological constant. The gravitational constant has been found to be linked with the geometrical Nieh-Yan density.

gr-qc↗

arXiv2006

de Sitter group and Einstein-Hilbert Lagrangian

Axial vector torsion in the Einstein-Cartan space $U_{4}$ is considered here. By picking a particular term from the SO(4,1) Pontryagin density and then modifying it in a SO(3,1) invariant way, we get a Lagrangian density with Lagrange multipliers. Then considering torsion and torsion-less connection as independent fields, it has been found that $κ$ and $λ$ of Einstein-Hilbert Lagrangian, appear as integration constants in such a way that $κ$ has been found to be linked with the topological Nieh-Yan density of $U_{4}$ space.

gr-qc↗