Stability of anisotropic superconducting phases in UPt_{3}

We have calculated the relative stability of s-, p-, and d-wave superconducting states in ${\mathrm{UPt}}_3$. This is done by fitting the observed spin-fluctuation spectrum by a simple form and taking the exchange of these fluctuations as the pairing mechanism. One representative of each of the above classes of states can occur, the stability depending on the Coulomb pseudopotential, the details of the fluctuation spectrum, and the Fermi surface. The most favorable gap function for the d-wave representations has two lines of nodes.