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pro vyhledávání: '"Keum, JongHae"'
Autor:
Keum, JongHae, Lee, Kyoung-Seog
In this paper, we suggest a new approach to study minimal surfaces of general type with $p_g=0$ via their Cox rings, especially using the notion of combinatorially minimal Mori dream space introduced by Hausen. First, we study general properties of c
Externí odkaz:
http://arxiv.org/abs/2206.02913
Autor:
Keum, JongHae, Oguiso, Keiji
We will show that there is a smooth complex projective surface, birational to some Enriques surface, such that the automorphism group is discrete but not finitely generated.
Comment: 12 printed pages, typos are corrected and make some minor modi
Comment: 12 printed pages, typos are corrected and make some minor modi
Externí odkaz:
http://arxiv.org/abs/1904.04451
Autor:
Keum, JongHae, Lee, Kyoung-Seog
In this paper we study effective, nef and semiample cones of minimal surfaces of general type with $p_g=0.$ We provide examples of minimal surfaces of general type with $p_g=0, 2 \leq K^2 \leq 9$ which are Mori dream spaces. On these examples we also
Externí odkaz:
http://arxiv.org/abs/1804.08382
Autor:
Borisov, Lev A., Keum, JongHae
Publikováno v:
Duke Math. J. 169, no. 6 (2020), 1135-1162
Fake projective planes are smooth complex surfaces of general type with Betti numbers equal to those of the usual projective plane. They come in complex conjugate pairs and have been classified as quotients of the two-dimensional ball by explicitly w
Externí odkaz:
http://arxiv.org/abs/1802.06333
Autor:
Catanese, Fabrizio, Keum, JongHae
We show, for several fake projective planes with nontrivial automorphism group, that the bicanonical map is an embedding.
Comment: A new section (Section 6) is added to point out that, due to many wrong proofs, the main result of the paper by S.
Comment: A new section (Section 6) is added to point out that, due to many wrong proofs, the main result of the paper by S.
Externí odkaz:
http://arxiv.org/abs/1801.05291
Autor:
Keum, JongHae
We prove that the bicanonical map of the Cartwright-Steger surface is an embedding. We also discuss two minimal surfaces of general type, both covered by the Cartwright-Steger surface. One has $K^2=2$, $p_g=1$, $\pi_1=\{1\}$ and the other has $K^2=1$
Externí odkaz:
http://arxiv.org/abs/1801.00733
If an automorphism of a projective K3 surface with Picard number 2 is of infinite order, then the automorphism corresponds to a solution of Pell equation. In this paper, by solving this equation, we determine all Salem polynomials of symplectic and a
Externí odkaz:
http://arxiv.org/abs/1711.02822
Autor:
Borisov, Lev, Keum, JongHae
In this short note we announce explicit equations of a fake projective plane in its bicanonical embedding in $\mathbb C\mathbb P^9$.
Comment: 2 pages + 2 pages of tables
Comment: 2 pages + 2 pages of tables
Externí odkaz:
http://arxiv.org/abs/1710.04501
Publikováno v:
J. Lond. Math. Soc. (2) 92 (2015), no. 3, 724--735
Let $X$ be a projective surface or a hyperk\"ahler manifold and $G \le Aut(X)$. We give a necessary and sufficient condition for the existence of a non-trivial $G$-equivariant fibration on $X$. We also show that two automorphisms $g_i$ of positive en
Externí odkaz:
http://arxiv.org/abs/1509.02996
Publikováno v:
Science China Mathematics 58 (2015) 501-512
We present the complete list of all singularity types on Gorenstein $\mathbb{Q}$-homology projective planes, i.e., normal projective surfaces of second Betti number one with at worst rational double points. The list consists of $58$ possible singular
Externí odkaz:
http://arxiv.org/abs/1502.02104