We present a model in which the breackdown of conformal symmetry of a quantum stress-tensor due to the trace anomaly is related to a cosmological effect in a gravitational model. This is done by characterizing the traceless part of the quantum stress-tensor in terms of the stress-tensor of a conformal invariant classical scalar field. We introduce a conformal frame in which the anomalous trace ...

In this paper, a novel conserved Lorentz covariant tensor, termed the helicity is introduced in Maxwell theory. The conservation of tensor expresses laws contained array, by Cameron et al., including helicity, spin, and spin-flux or infra-zilch. covariance contrast to previous formulations hierarchy laws, which required non-Lorentz transverse gauge. shown arise as Noether current for variationa...

We report the existence of novel static spherical black-hole solutions in a vector-tensor gravitational theory called bumblebee gravity model which extends Einstein-Maxwell by allowing vector to nonminimally couple Ricci curvature tensor. A test strong-field regime is performed for first time using recent observations supermassive shadows galaxy M87 and Milky Way from Event Horizon Telescope Co...

Critical gravitational collapse was first found by Choptuik[1] in simulations of a spherically symmetric massless scalar field. A natural question to pose is then how critical collapse behaves when the scalar field has a mass, since this will introduce a characteristic length that destroys the scale invariance of the field equations. This question was studied by Brady et. al.[2] The results of ...

We study the general gaugings of N = 2 Maxwell-Einstein supergravity theories (MESGT) in five dimensions, extending and generalizing previous work. The global symmetries of these theories are of the form SU(2)R×G, where SU(2)R is the R-symmetry group of the N = 2 Poincaré superalgebra and G is the group of isometries of the scalar manifold that extend to symmetries of the full action. We first ...