The making of Calabi‐Yau spaces: Beyond toric hypersurfaces

Abstract While Calabi‐Yau hypersurfaces in toric ambient spaces provide a huge number of examples, theoretical considerations as well as applications to string phenomenology often suggest a broader perspective. With even the question of finiteness of diffeomorphism types of CY 3‐folds unsettled, an important idea is Reid's conjecture that the moduli spaces are connected by certain singular transitions. We summarize the results of our recent construction of a large class of new CY spaces with small Picard numbers and of their mirrors via conifold transitions and discuss the benefits of other approaches to interesting locations in the web that have been or should be pursued.