88 citations · 243 across the 25 of their papers we have counts for
30 papers
Degree of irrationality of a product of two elliptic curves
Yongnam Lee
In this short paper, we prove that, for any two complex elliptic curves \(E\) and \(F\), the product \(E\times F\) has degree of irrationality \(3\). The upper bound is obtained fr…
Degree of irrationality of properly elliptic surfaces
Yongnam Lee, De-Qi Zhang
In this paper, we study the degree of irrationality of properly elliptic surfaces with a section. We prove $\min\{χ(\mathcal O_S),\,2\operatorname{gon}(C)\} \leq \operatorname{irr}…
Deformation of pairs of and hypersurfaces
Jungkai Chen, Yongnam Lee, Phin-Sing Soo
Motivated by DeVleming's work on moduli of surfaces in and Chen-Hu-Jiang's work on moduli of threefolds with volume and geometric genus , we study the deforma…
Smooth projective surfaces with pseudo-effective tangent bundles
Jia Jia, Yongnam Lee, Guolei Zhong
Let be a non-uniruled (i.e., non-birationally ruled) smooth projective surface. We show that the tangent bundle is pseudo-effective if and only if the canonical divisor $…
Lagrangian fibration structure on the cotangent bundle of a del Pezzo surface of degree 4
Hosung Kim, Yongnam Lee
In this paper, we show that there is a natural Lagrangian fibration structure on the map from the cotangent bundle of a del Pezzo surface of degree 4 to . More…
Bigness of the tangent bundle of a Fano threefold with Picard number two
Hosung Kim, Jeong-Seop Kim, Yongnam Lee
In this paper, we study the positivity property of the tangent bundle of a Fano threefold with Picard number 2. We determine the bigness of the tangent bundle of the whol…