LRS Bianchi type I universes exhibiting Noether symmetry in the scalar-tensor Brans-Dicke theory

Understand

Following up on hints of anisotropy in the cosmic microwave background radiation (CMB) data, we investigate locally rotational symmetric (LRS) Bianchi type I spacetimes with non-minimally coupled scalar fields.

• To single out potentially more interesting solutions, we search for Noether symmetry in this system.
• We then specialize to the Brans-Dicke (BD) field in such a way that the Lagrangian becomes degenerate (nontrivial) and solve the equations for Noether symmetry and the potential that allows it.
• Then we find the exact solutions of the equations of motion in terms of three parameters and an arbitrary function.