Invariants of curves in RP^2 and R^2

Abigail Thompson

doi:10.2140/agt.2006.6.2175

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arXiv · math/0602003

Invariants of curves in RP^2 and R^2

Abigail Thompson

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Abstract

There is an elegant relation found by Fabricius-Bjerre [Math. Scand 40 (1977) 20--24] among the double tangent lines, crossings, inflections points, and cusps of a singular curve in the plane. We give a new generalization to singular curves in RP^2. We note that the quantities in the formula are naturally dual to each other in RP^2, and we give a new dual formula.

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BibTeX RIS

Abigail Thompson. 2009-06-30. Invariants of curves in RP^2 and R^2. https://doi.org/10.2140/agt.2006.6.2175

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