Kristian Ranestad

Kristian Ranestad is a Professor at the Department of Mathematics, University of Oslo. He specializes in Algebraic Geometry with a focus on projective algebraic geometry, particularly surfaces in four-dimensional space, varieties of small codimension, hyperkähler varieties, and abelian varieties. His work also explores applications in elliptic curve cryptography, phylogeny, and semidefinite programming.

His research interests span a wide range of topics including the geometry of algebraic varieties, moduli spaces, and computational algebraic geometry. Notably, he has contributed to studies on canonical forms, spectrahedra, and the convex hulls of algebraic surfaces. He collaborates extensively with researchers like Bernd Sturmfels, Frank-Olaf Schreyer, and others, focusing on problems at the intersection of algebra, geometry, and optimization.

Ranestad has advised numerous PhD students, including Martin Helsø, Elise Øby, and Johannes Kleppe, whose theses cover topics like determinantal quartic hypersurfaces and apolar varieties. His recent work includes studies on adjoints of algebraic varieties, quartic spectrahedra, and the geometry of cubic surfaces.

His publications highlight advancements in understanding varieties of sums of powers, the algebraic degree of optimization problems, and the geometry of moduli spaces. Despite no explicitly listed awards, his contributions have been recognized through invited lectures and editorial roles in leading journals.