What does it mean to put $\sqrt{\phantom{-v}}$ alone below a square rooted expression?

Question

In Yaremenko's paper here, on the 5th page of the pdf, which is page ten, in section IV, he uses a square root symbol alone under $\sqrt{-g}$ and $\sqrt {-g} \, dV$. What does this mean?

Answer 1

Both underset, empty radicals are typos. If they were not typos a third one would appear in the last display of the cited page attached to the last term in the parentheses. There it isn't. Ignore them.