A scalar-tensor theory of gravity, containing an arbitrary coupling function F (ϕ) and a
general potential V (ϕ), is considered in the context of a spatially flat Friedmann-Lemaître …

We give a general method to find exact cosmological solutions for scalar-field dark energy in
the presence of perfect fluids. We use the existence of invariant transformations for the …

We consider the two scalar field cosmology in a Friedmann Robertson Walker spatially flat
spacetime where the scalar fields interact both in the kinetic part and the potential. We apply …

We consider the application of the theory of symmetries of coupled ordinary differential
equations to the case of reparametrization invariant Lagrangians quadratic in the velocities; …

This volume summarizes the many alternatives and extensions to Einstein's General Theory
of Relativity, and shows how symmetry principles can be applied to identify physically viable …

We present a unified description of the matter and dark energy epochs using a class of
scalar-torsion theories. We provide a Hamiltonian description, and by applying Noether's …

We consider f (R)-gravity in a Friedmann–Lemaître–Robertson–Walker spacetime with zero
spatial curvature. We apply the Killing tensors of the minisuperspace in order to specify the …

Exact and analytic solutions in Einstein–Aether scalar field theory with Kantowski–Sachs
background space are determined. The theory of point symmetries is applied to determine …

We consider modified teleparallel gravity (f (T) gravity), as a framework to explain the
present accelerated expansion of the universe. The matter component is assumed to be cold …

In the context of generalized Brans-Dicke cosmology we use the Killing tensors of the
minisuperspace in order to determine the unspecified potential of a scalar-tensor gravity …