Abstract
The paper is based on the lecture course “Metric projective geometry” which I conducted at the summer school “Finsler geometry with applications” at Karlovassi, Samos, in 2014, and at the workshop before the 8th seminar on Geometry and Topology of the Iranian Mathematical society at the Amirkabir University of Technology in 2015. The goal of this lecture course was to show how effective projectively invariant objects can be used to solve natural and named problems in differential geometry, and this paper also does it: I give easy new proofs to many known statements and also prove the following new statement: on a complete Riemannian manifold on nonconstant curvature, the index of the group of affine transformations in the group of projective transformations is at most two.
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\(8{\text{ th }}\) Seminar on Geometry and Topology, Amirkabir University of Technology, December 15–17, 2015.
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Matveev, V.S. Projectively Invariant Objects and the Index of the Group of Affine Transformations in the Group of Projective Transformations. Bull. Iran. Math. Soc. 44, 341–375 (2018). https://doi.org/10.1007/s41980-018-0024-y
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DOI: https://doi.org/10.1007/s41980-018-0024-y
Keywords
- Projectively equivalent metrics
- Geodesically equivalent metrics
- Projective connection
- Projectively invariant equations
- Integrable systems
- Killing tensors
- Projective Lichnerowicz conjecture

