A quasi-exact formula for Ising critical temperatures on hypercubic lattices

We report a quasi-exact power law behavior for Ising critical temperatures on hypercubes. It reads J/kBTc = K0[(1 − 1/d)(q−1)]a where K0 = 0.8633747, d is the space dimension q the coordination number (q = 2d), J the coupling constant kB the Boltzman constant and Tc the critical temperature. Absolute errors from available exact estimates (d=2−7) are always less than 0.0005. Extension to other lattice is discussed.