FORTSCHRITTE DER PHYSIK-PROGRESS OF PHYSICS
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The quintic family must be the most studied family of Calabi-Yau threefolds. Particularly symmetric members of this family are known to admit quotients by freely acting symmetries isomorphic to Z5×Z5. The corresponding quotient manifolds may themselves be symmetric. That is, they may admit symmetries that descend from the symmetries that the manifold enjoys before the quotient is taken. The formalism for identifying these symmetries was given a long time ago by Witten and instances of these symmetric quotients were given also, for the family P7[2,2,2,2], by Goodman and Witten. We rework this calculation here, with the benefit of computer assistance, and provide a complete classification. Our motivation is largely to develop methods that apply also to the analysis of quotients of other CICY manifolds, whose symmetries have been classified recently. For the Z5×Z5quotients of the quintic family, our list contains families of smooth manifolds with symmetry Z4,Dic3and Dic5, families of singular manifolds with four conifold points, with symmetry Z6and Q8, and rigid manifolds, each with at least a curve of singularities, and symmetry Z10. We intend to return to the computation of the symmetries of the quotients of other CICYs elsewhere.
Submitted to ORA: