343 citations
- Kazan Federal UniversityRU5 papers
- Norwegian University of Science and TechnologyNO4 papers
- Centre for Advanced StudyNO3 papers
- Centre National de la Recherche ScientifiqueFR3 papers
- Delft University of TechnologyNL3 papers
- University of BaselCH3 papers
- University of StuttgartDE3 papers
- Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)DE2 papers
- Leiden UniversityNL2 papers
- Ludwig-Maximilians-Universität MünchenDE2 papers
- National Hellenic Research FoundationGR2 papers
- Universität UlmDE2 papers
8 papers · 1 filter
Closures of quadratic modules
Jaka Cimpric, Murray Marshall, Tim Netzer
We consider the problem of determining the closure of a quadratic module M in a commutative R-algebra with respect to the finest locally convex topology. This is of interest in dec…
Sums of squares on reducible real curves
Daniel Plaumann
We ask whether every polynomial function that is non-negative on a real algebraic curve can be expressed as a sum of squares in the coordinate ring. Scheiderer has classified all i…
Stability of Quadratic Modules
Tim Netzer
A finitely generated quadratic module or preordering in the real polynomial ring is called stable, if it admits a certain degree bound on the sums of squares in the representation…
Cox rings and combinatorics
Florian Berchtold, Juergen Hausen
For a variety with a finitely generated total coordinate ring, we describe basic geometric properties in terms of certain combinatorial structures living in its divisor class group…
Combinatorial Duality and Intersection Product: A Direct Approach
Gottfried Barthel, Jean-Paul Brasselet, Karl-Heinz Fieseler +1
The proof of the combinatorial Hard Lefschetz Theorem for the ``virtual'' intersection cohomology of a not necessarily rational polytopal fan that has been presented by K. Karu com…
Homogeneous coordinates for algebraic varieties
Florian Berchtold, Juergen Hausen
We associate to every divisorial (e.g. smooth) variety with only constant invertible global functions and finitely generated Picard group a -graded homogeneous coordina…