Borel-Pad\'e re-summation of the $\beta$-functions describing Anderson localisation in the Wigner-Dyson symmetry classes
We describe a Borel-Pad\'e re-summation of the $\beta$-function in the three Wigner-Dyson symmetry classes. Using this approximate $\beta$-function we discuss the dimensional dependence of the critical exponent and compare with numerical estimates. We also estimate the lower critical dimension of the symplectic symmetry class.