Exact Cosmological Solutions of $f(R)$ Theories via Hojman Symmetry

Understand

Nowadays, $f(R)$ theory has been one of the leading modified gravity theories to explain the current accelerated expansion of the universe, without invoking dark energy.

• It is of interest to find the exact cosmological solutions of $f(R)$ theories.
• Besides other methods, symmetry has been proved as a powerful tool to find exact solutions.
• On the other hand, symmetry might hint the deep physical structure of a theory, and hence considering symmetry is also well motivated.