Displaying similar documents to “A note on the saddle conic of quadratic planar differential systems.”

Affine invariant conditions for the topological distinction of quadratic systems with a critical point of the 4th multiplicity.

Mark Voldman, Iu. T. Calin, Nicolae I. Vulpe (1996)

Publicacions Matemàtiques

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The affine invariant partition of the set of quadratic systems with one finite singular point of the 4th multiplicity with respect to different topological classes is accomplished. The conditions corresponding to this partition are semi-algebraic, i.e. they are expressed as equalities or inequalities between polynomials.

Affine invariants of annuli

Waldemar Cieślak, Elzbieta Szczygielska (2012)

Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica

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A family of regular annuli is considered. Affine invariants of annuli are introduced.

Curvature functionals for curves in the equi-affine plane

Steven Verpoort (2011)

Czechoslovak Mathematical Journal

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After having given the general variational formula for the functionals indicated in the title, the critical points of the integral of the equi-affine curvature under area constraint and the critical points of the full-affine arc-length are studied in greater detail. Notice. An extended version of this article is available on arXiv:0912.4075.

Affine invariants of annuli

Waldemar Cieślak, Elżbieta Szczygielska (2012)

Annales UMCS, Mathematica

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A family of regular annuli is considered. Affine invariants of annuli are introduced.