3 papers
math.AG2026
Desmic quartic surfaces in arbitrary characteristic
Igor Dolgachev, Shigeyuki Kondo
A desmic quartic surface is a birational model of the Kummer surface of the self-product of an elliptic curve. We recall the classical geometry of these surfaces and study their an…
math.AG2025
Bitangent surfaces and involutions of quartic surfaces
Igor Dolgachev, Shigeyuki KondÅ, Shigeyuki Kondō
We study the congruence of bitangent lines of an irreducible surface in the 3-dimensional projective space in arbitrary characteristic, with special attention to quartic surfaces w…
math.AG2025
K3 surfaces of degree six arising from desmic tetrahedra
Alex Degtyarev, Igor Dolgachev, Shigeyuki Kondo
We study K3 surfaces of degree 6 containing two sets of 12 skew lines such that each line from a set intersects exactly six lines from the other set. These surfaces arise as hyperp…