EN
Let K be a number field. Assume that the 2-rank of the ideal class group of K is equal to the 2-rank of the narrow ideal class group of K. Moreover, assume K has a unique dyadic prime 𝔡 and the class of 𝔡 is a square in the ideal class group of K. We prove that if 𝔭₁,...,𝔭ₙ are finite primes of K such that
∙ the class of $𝔭_i$ is a square in the ideal class group of K for every i ∈ {1,...,n},
∙ -1 is a local square at $𝔭_i$ for every nondyadic $𝔭_i ∈ {𝔭₁,...,𝔭ₙ}$,
then {𝔭₁,...,𝔭ₙ} is the wild set of some self-equivalence of the field K.