Crofton's and poincaré's formulas in the Lorentzian plane

The purpose of the present paper is to compare some of the formulas of integral geometry in the Euclidean plane with those for the Lorentzian plane. In particular, we find that the so-called Crofton's formula and Poincaré's formula hold only under the restrictions expressed in Theorems 1 a...

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Detalles Bibliográficos
Autor principal: Birman, Graciela Silvia
Publicado: 1984
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00465755_v15_n4_p399_Birman
http://hdl.handle.net/20.500.12110/paper_00465755_v15_n4_p399_Birman
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Sumario:The purpose of the present paper is to compare some of the formulas of integral geometry in the Euclidean plane with those for the Lorentzian plane. In particular, we find that the so-called Crofton's formula and Poincaré's formula hold only under the restrictions expressed in Theorems 1 and 2, respectively. In order to arrive at these results, we find several different expressions for the density of geodesics and kinematic density. © 1984 D. Reidel Publishing Company.