singular collineation
1Collineation — In projective geometry, a collineation is a one to one and onto map (a bijection) from one projective space to another, or from a projective space to itself, such that the images of collinear points are themselves collinear. All projective linear …
2Orbifold — This terminology should not be blamed on me. It was obtained by a democratic process in my course of 1976 77. An orbifold is something with many folds; unfortunately, the word “manifold” already has a different definition. I tried “foldamani”,… …
3Geometry — (Greek γεωμετρία ; geo = earth, metria = measure) is a part of mathematics concerned with questions of size, shape, and relative position of figures and with properties of space. Geometry is one of the oldest sciences. Initially a body of… …
