29 citations · 215 across the 37 of their papers we have counts for
6 papers · 1 filter
Nodes on quintic spectrahedra
Taylor Brysiewicz, Khazhgali Kozhasov, Mario Kummer
We classify transversal quintic spectrahedra by the location of 20 nodes on the respective real determinantal surface of degree 5. We identify 65 classes of such surfaces and find…
A generalization of the space of complete quadrics
Abeer Al Ahmadieh, Mario Kummer, Miruna-Stefana Sorea
To any homogeneous polynomial we naturally associate a variety which maps birationally onto the graph of the gradient map and which agrees with the space…
Spectral linear matrix inequalities
Mario Kummer
We prove, under a certain representation theoretic assumption, that the set of real symmetric matrices, whose eigenvalues satisfy a linear matrix inequality, is itself a spectrahed…
Positive Ulrich Sheaves
Christoph Hanselka, Mario Kummer
We provide a criterion for a coherent sheaf to be an Ulrich sheaf in terms of a certain bilinear form on its global sections. When working over the real numbers we call it a positi…
Rational functions with only real periodic points
Khazhgali Kozhasov, Mario Kummer
We study self-morphisms of smooth real projective algebraic curves that have only real periodic points. In the case of the projective line we provide a convenient characterization…
Hyperbolic Secant Varieties of M-Curves
Mario Kummer, Rainer Sinn
We relate the geometry of curves to the notion of hyperbolicity in real algebraic geometry. A hyperbolic variety is a real algebraic variety that (in particular) admits a real fibe…