Physics Letters B (Apr 2020)
Generalized cosmological constant from gauging Maxwell-conformal algebra
Abstract
The Maxwell extension of the conformal algebra is presented. With the help of gauging the Maxwell-conformal group, a conformally invariant theory of gravity is constructed. In contrast to the conventional conformally invariant actions, our gravitational action contains the Einstein-Hilbert term without introducing any additional (compensator) scalar field to satisfy the local scale invariance. This is achieved by using the curvatures of the algebra. In a special condition, we show that the resulting action is reduced to the Brans-Dicke like theory of gravity. We subsequently find the generalized Einstein field equation together with a coordinate dependent cosmological term and additional contributions. Keywords: Lie algebra, Gauge field theory, Modified theory of gravity, Cosmological constant