3 papers
math.AG2026
Non-general type surfaces in P4, an update
Hirotachi Abo, Kristian Ranestad, Frank-Olaf Schreyer
A general algebraic surface cannot be embedded in P4. Proving a conjecture by Hartshorne and Lichtenbaum, Ellingsrud and Peskine showed that there is a degree bound for smooth rati…
math.OC2026
Algebraic Degrees of Generalized Nash Equilibrium Problems
Jiawang Nie, Kristian Ranestad, Xindong Tang
This paper studies the algebraic degree of generalized Nash equilibrium problems (GNEPs) given by polynomials. Their generalized Nash equilibria (GNEs), as well as their KKT or Fri…
math.AG2024
Adjoints and Canonical Forms of Polypols
Kathlén Kohn, Ragni Piene, Kristian Ranestad +5
Polypols are natural generalizations of polytopes, with boundaries given by nonlinear algebraic hypersurfaces. We describe polypols in the plane and in 3-space that admit a unique…