Notes on Mitsui's Prime Number Theorem with Siegel zeros

In these notes, we refine Mitsui's Prime Number Theorem from 1957, which for a number field $K$ predicts how many prime elements there are in bounded convex sets in $K \otimes_{\mathbf Q} \mathbf R$, by incorporating potential Siegel zeros of Hecke L-functions. This allows the norm of the modulus $\mathbf N (\mathfrak q)$ to grow at a pseudopolynomial rate with respect to the size $X$ of the convex set as opposed to powers of $\log X$. The extra flexibility and precision will be essential in our future application to the study of linear patterns of prime elements. We also hope that our updated exposition will make Mitsui's work accessible to a wider mathematical audience.