4 papers
Helicity, Spin, and Infra-zilch of Light: a Lorentz Covariant Formulation
Sajad Aghapour, Lars Andersson, Kjell Rosquist
In this paper, a novel conserved Lorentz covariant tensor, termed the helicity tensor, is introduced in Maxwell theory. The conservation of the helicity tensor expresses the conser…
The Zilch Electromagnetic Conservation Law Revisited
Sajad Aghapour, Lars Andersson, Kjell Rosquist
It is shown that the zilch conservation law arises as the Noether current corresponding to a variational symmetry of a duality-symmetric Maxwell Lagrangian. The action of the corre…
Helicity and spin conservation in Maxwell theory and Linearized Gravity
Sajad Aghapour, Lars Andersson, Reebhu Bhattacharyya
A duality symmetric formulation of linearized gravity has been introduced by Barnett and used to show the conservation of helicity. However, the relation between helicity and spin…
On variational principle and canonical structure of gravitational theory in double-foliation formalism
Sajad Aghapour, Ghadir Jafari, Mehdi Golshani
In this paper, we analyze the variation of the gravitational action on a bounded region of spacetime whose boundary contains segments with various characters, including null. We de…