We consider an extended theory of gravity with Lagrangian ℒ = f(R,T(n)), with T(n) being a 2nth-order invariant made of contractions of the energy-momentum tensor. When n = 1, this theory reduces to f(R,T) gravity, where T accounts for the trace of the energy-momentum tensor. We study the gravitational wave polarization modes, from which it results that when the matter Lagrangian contains dynamical scalar fields minimally coupled to the geometry, further polarization modes arise with respect to General Relativity. Finally, we show that the motion for test particles is nongeodesic and we explicitly obtain the extra force.
Linearized field equations and extra force in f (R, T (n)) extended gravity / Capozziello, Salvatore. - In: INTERNATIONAL JOURNAL OF MODERN PHYSICS D. - ISSN 0218-2718. - (2022). [10.1142/S0218271822400156]
Linearized field equations and extra force in f (R, T (n)) extended gravity
Capozziello
2022
Abstract
We consider an extended theory of gravity with Lagrangian ℒ = f(R,T(n)), with T(n) being a 2nth-order invariant made of contractions of the energy-momentum tensor. When n = 1, this theory reduces to f(R,T) gravity, where T accounts for the trace of the energy-momentum tensor. We study the gravitational wave polarization modes, from which it results that when the matter Lagrangian contains dynamical scalar fields minimally coupled to the geometry, further polarization modes arise with respect to General Relativity. Finally, we show that the motion for test particles is nongeodesic and we explicitly obtain the extra force.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.