Weak angle from Kaluza-Klein theory with deformed internal space

We study a seven-dimensional Kaluza-Klein theory with a three-dimensional Taub space as internal manifold. The electroweak coupling constant ratio is shown to be relatable to the deformation parameter α (shape) of the internal space. The full deformation range yields a weak angle in the range 0.25 < sin2θw < 1. Using the value of α (=-0.2133) from a solution of the Einstein equations with quantum vacuum sources, we get sin2θw = 0.511. (orig.)