Conics and Quadrics in Lorentzian Space

Rational Families of Conics and Quadrics

A surface generated by a one parameter family of conics c(t) is called conic surface. If c(t) can be described by rational functions, the generated conic surface is rational. An algorithm to construct real rational parametrizations for such surfaces and some examples will be given.

Sums of Squares in Function Fields of Quadrics and Conics

For a quadric Q over a real field k, we investigate whether finiteness of the Pythagoras number of the function field k(Q) implies the existence of a uniform bound on the Pythagoras numbers of all finite extensions of k. We give a positive answer if the quadratic form that defines Q is weakly isotropic. In the case where Q is a conic, we show that the Pythagoras number of k(Q) is 2 only if k is...

The projective reconstruction of points, lines, quadrics, plane conics and degenerate quadrics using uncalibrated cameras

In this paper we present an algorithm for the simultaneous projective reconstruction of points, lines, quadrics, plane conics and degenerate quadrics using Bundle Adjustment. In contrast, most existing work on projective reconstruction focuses mainly on one type of primitive. Furthermore, for the reconstruction of quadrics (both full-rank and degenerate) and plane conics, a novel algorithm for ...

Hypersurfaces with Constant Mean Curvature in a Lorentzian Space Form

Metric Problems for Quadrics in Multidimensional Space

Given the equations of the first and the second order surfaces in Rn, our goal is to construct a univariate polynomial one of the zeros of which coincides with the square of the distance between these surfaces. To achieve this goal we employ Elimination Theory methods. The proposed approach is also extended for the case of parameter dependent surfaces.