Ομιλητής: Josef Schicho (Johannes Kepler University Linz)
Ημέρα: 05-10-2018, 12:00
Μέρος: Δ, Τμήμα Πληροφορικής και Τηλεπικοινωνιών ΕΚΠΑ
An algebraic surface is given by its equation, the zero set of a polynomial in four homogeneous variables. Its picture under central projection is computed as the zero set of its discriminant: a plane algebraic curve. Can we recover the equation of an algebraic surface by its discriminant?
If the surface is nonsingular, then the answer is yes, by a result of d'Almeida. If we allow also "generic" singularities, then the there is sometimes a finite list of possibles. This talk explains the reconstruction method and discusses the ambiguities in the singular case.