3 papers
math.AG2025
Hierarchical structure of graded Betti numbers in the quadratic strand
Jong In Han, Sijong Kwak, Wanseok Lee
The classical results, initiated by Castelnuovo and Fano and later refined by Eisenbud and Harris, provide several upper bounds on the number of quadrics defining a nondegenerate p…
math.AG2025
Characterization of projective varieties beyond varieties of minimal degree and del Pezzo varieties
Jong In Han, Sijong Kwak, Euisung Park
Varieties of minimal degree and del Pezzo varieties are basic objects in projective algebraic geometry. Those varieties have been characterized and classified for a long time in ma…
math.AG2025
Surface counterexamples to the Eisenbud-Goto conjecture
Jong In Han, Sijong Kwak
It is well known that the Eisenbud-Goto regularity conjecture is true for arithmetically Cohen-Macaulay varieties, projective curves, smooth surfaces, smooth threefolds in $\mathbb…