Spherical quadrilaterals with three non-integer angles
arXiv:1504.02928
Abstract
We classify spherical quadrilaterals up to isometry in the case when one inner angle is a multiple of pi while the other three are not. This is equivalent to classification of Heun's equations with real parameters and one apparent singularity such that the monodromy consists of unitary transformations.
38 pages, 16 figures. arXiv admin note: text overlap with arXiv:1409.1529