Symmetric teleparallel cosmology with boundary corrections

Understand

We investigate the geometrodynamical effects of introducing the boundary term in symmetric teleparallel gravity.

• Specifically, we consider a homogeneous and isotropic universe in $f\left( Q, B \right) $, where $Q$ is the non-metricity scalar, and $B$ is the boundary term that relates the non-metricity and Ricci scalars.
• For the connection in the coincidence gauge, we find that the field equations are of fourth-order, and the fluid components introduced by the boundary are attributed to a scalar field.
• In the coincidence gauge, the cosmological field equations are equivalent to those of teleparallelism with a boundary term.