I have an expression where I have converted all units such that the answer is expressed in 4d Planck mass, $m_p^{(4d)}$.
In David Tong's lecture notes, Newtons gravitational constant in 4d is given by $ G \sim \frac{1}{m_p^{(4d)}}$.
How would I express this (or anything in terms of 4d Planck mass) in $m_p^{(3d)}$?
