A study of energy conditions in non-static spherically symmetric spacetimes via Noether symmetries

Integration of the geodesic equations via Noether symmetries

“…where prime ( ′ ) denotes derivative with respect to the radial coordinate r. All STH Riemannian manifolds endowed with the Gödel-type spacetime (10) are obtained by solving equations in (11) as follows:…”

“…In order to find out analytical solutions of geodesic equations for the considered geodesic Lagrangian, one can use the obtained first integrals of motion which are Noether constants. Recently the Noether symmetries of geodesic Lagrangian for some spacetimes have been calculated, and classified according to their Noether symmetry generators [3]- [11]. In this study we consider Noether symmetries (the approximate Noether symmetries) of the geodesic Lagrangian (the perturbed geodesic Lagrangian) for the line elements of some known spacetimes, rather than those of the geodesic equations.…”

Classification of static spherically symmetric perfect fluid space-times via conformal vector fields in f(T) gravity

“…The solutions deduced in this paper enjoy certain important physical properties that could be judged via energy conditions. It is well known that some sorts of energy conditions exist in the literature that help to select physically realistic solutions for the EFEs [103]. These conditions include the weak energy condition (WEC), strong energy condition (SEC), dominant energy condition (DEC) and null energy condition (NEC).…”