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Sur un théorème de M. Chasles concernant les coniques homofocales

Édouard Lucas (1880)

Nouvelles annales de mathématiques : journal des candidats aux écoles polytechnique et normale

The Euler number of the normalization of an algebraic threefold with ordinary singularities

Shoji Tsuboi (2004)

Banach Center Publications

By a classical formula due to Enriques, the Euler number χ(X) of the non-singular normalization X of an algebraic surface S with ordinary singularities in P³(ℂ) is given by χ(X) = n(n²-4n+6) - (3n-8)m + 3t - 2γ, where n is the degree of S, m the degree of the double curve (singular locus) $D_{S}$ of S, t is the cardinal number of the triple points of S, and γ the cardinal number of the cuspidal points of S. In this article we shall give a similar formula for an algebraic threefold with ordinary singularities...

The multiple conical surfaces.

Schicho, Josef (2001)

Beiträge zur Algebra und Geometrie

Tissus du plan et polynômes de Darboux

Olivier Ripoll, Julien Sebag (2010)

Annales de la faculté des sciences de Toulouse Mathématiques

Dans cet article, nous étudions le problème de l’existence de polynômes de Darboux dans $C {x} [y, y^{'}]$ pour la dérivation $δ = R (y) \partial_{x} + R (y) y^{'} \partial_{y} - V (y, y^{'}) \partial_{y^{'}}$ .

Классификация конфигураций ранга восемь

И.В. Лях (1979)

Matematiceskie issledovanija

Рациональные поверхности с пучком рациональных кривых

В.А. Исковских (1967)

Matematiceskij sbornik