Cosmological solutions of a chiral self-gravitating model of $f(R,(\nabla R{)}^2,\square R)$ gravity

Tatyana Chaadaeva, Sergey Chervon

We study modified $f(R,(\nabla R{)}^2,\square R)$ gravity and show in detail how it can be reduced to Einstein gravity with a few scalar fields and then represented in the form of ch…