Many papers show how the Weinberg angle (the weak mixing angle in the electroweak interaction) changes with energy / momentum transfer. One is https://arxiv.org/abs/1107.4683 and shows that sin^2 theta_W starts at 0.238 at low energy, reduces to 0.232 at around 100 GeV and goes back to 0.238 at 1000 GeV.
But the curves stop at around 1000 GeV. Is there a theoretical prediction about how the value changes for higher energies / momentum transfers? I am looking for a curve that ideally would go up to Planck energy - or at least to the GUT scale.