Constraining Quadratic $f(R)$ Gravity from Astrophysical Observations of the Pulsar J0704+6620

G. G. L. Nashed, Waleed El Hanafy

We apply quadratic $f(R)=R+\epsilon R^2$ field equations, where $\epsilon$ has a dimension [L${}^2$], to static spherical stellar model. We assume the interior configuration is determined by Krori-…