80 citations · 232 across the 22 of their papers we have counts for
25 papers
Stubborn Polynomials
Lorenzo Baldi, Grigoriy Blekherman, Khazhgali Kozhasov +3
The relationship between nonnegative polynomials and sums of squares is a classical topic in real algebraic geometry. We study \emph{stubborn polynomials} on a real variety …
Totally real divisors on curves
Lorenzo Baldi, Mario Kummer, Daniel Plaumann
Since the works of Krasnov and Scheiderer, there has been an interest in studying effective totally real divisors on a curve X defined over a real closed field, i.e., effective div…
Plane quartics and heptagons
Daniele Agostini, Daniel Plaumann, Rainer Sinn +1
Every polygon with n vertices in the complex projective plane is naturally associated with its adjoint curve of degree n-3. Hence the adjoint of a heptagon is a plane quartic. We p…
Computing totally real hyperplane sections and linear series on algebraic curves
Huu Phuoc Le, Dimitri Manevich, Daniel Plaumann
Given a real algebraic curve, embedded in projective space, we study the computational problem of deciding whether there exists a hyperplane meeting the curve in real points only.…
Families of faces and the normal cycle of a convex semi-algebraic set
Daniel Plaumann, Rainer Sinn, Jannik Lennart Wesner
We study families of faces for convex semi-algebraic sets via the normal cycle which is a semi-algebraic set similar to the conormal variety in projective duality theory. We propos…
Kippenhahn's Theorem for joint numerical ranges and quantum states
Daniel Plaumann, Rainer Sinn, Stephan Weis
Kippenhahn's Theorem asserts that the numerical range of a matrix is the convex hull of a certain algebraic curve. Here, we show that the joint numerical range of finitely many Her…