Root discriminant

The root discriminant of a number field \(K\) is \(\mathrm{rd}(K)= (|\Delta_{K}|)^{\frac{1}{\deg K}}\) where \(\Delta_{K}\) is the discriminant of the number field.

For any number field, \(\mathrm{rd}(K)\) is bounded from below due to Odlyzko’s bounds. See this pdf for a nice overview.