Zobrazeno 1 - 10
of 45
pro vyhledávání: '"Uehara, Hokuto"'
Autor:
Takashima, Yuta, Uehara, Hokuto
We establish a one-to-one correspondence between the singularity categories of rational double points and the simply-laced Dynkin graphs in arbitrary characteristic. This correspondence is well-known in characteristic zero since the rational double p
Externí odkaz:
http://arxiv.org/abs/2408.02532
Autor:
Uehara, Hokuto, Watanabe, Tomonobu
The first author explicitly describes the set of Fourier--Mukai partners of elliptic ruled surfaces over the complex number field in \cite{Ue17}. In this article, we generalize it over arbitrary characteristic fields. We also obtain a partial evidenc
Externí odkaz:
http://arxiv.org/abs/2307.04281
Autor:
Togashi, Takato, Uehara, Hokuto
Atiyah classifies vector bundles on elliptic curves $E$ over an algebraically closed field of any characteristic. On the other hand, a rank $2$ vector bundle on $E$ defines a surface $S$ with a $\mathbb{P}^1$-bundle structure on $E$. We study when $S
Externí odkaz:
http://arxiv.org/abs/2212.00304
Structure theorems for exceptional objects and exceptional collections of the bounded derived category of coherent sheaves on del Pezzo surfaces are established by Kuleshov and Orlov. In this paper we propose conjectures which generalize these result
Externí odkaz:
http://arxiv.org/abs/2107.03051
Autor:
Uehara, Hokuto
We study autoequivalence groups of the derived categories on smooth projective surfaces, and show a trichotomy of types according to the maximal dimension of Fourier--Mukai kernels for autoequivalences. This number is $2$, $3$ or $4$, and we also pos
Externí odkaz:
http://arxiv.org/abs/1704.00292
Autor:
Uehara, Hokuto
We study Fourier--Mukai partners of elliptic ruled surfaces. We also describe the autoequivalence group of the derived categories of ruled surfaces with an elliptic fibration, by using \cite{Ue15}.
Comment: 15 pages. arXiv admin note: substantia
Comment: 15 pages. arXiv admin note: substantia
Externí odkaz:
http://arxiv.org/abs/1511.06031
Autor:
Uehara, Hokuto
We study the group of autoequivalences of the derived categories of coherent sheaves on smooth projective elliptic surfaces with non-zero Kodaira dimensions. We find a description of it when each reducible fiber is a cycle of $(-2)$-curves.
Comm
Comm
Externí odkaz:
http://arxiv.org/abs/1501.06657
Autor:
Okawa, Shinnosuke, Uehara, Hokuto
Publikováno v:
International Mathematics Research Notices; First published online: March 26, 2015
We investigate exceptional sheaves on the Hirzebruch surface $\mathbb{F}_2$, as the first attempt toward the classification of exceptional objects on weak del Pezzo surfaces.
Comment: 25 pages
Comment: 25 pages
Externí odkaz:
http://arxiv.org/abs/1409.7813
Autor:
Ohkawa, Ryo, Uehara, Hokuto
Publikováno v:
Adv. Math. 244 (2013) 241--267
For a toric Deligne-Mumford (DM) stack, we can consider a certain generalization of the Frobenius endomorphism. For such an endomorphism on a two-dimensional toric DM stack, we show that the push-forward of the structure sheaf generates the bounded d
Externí odkaz:
http://arxiv.org/abs/1205.6861
Autor:
Uehara, Hokuto
Publikováno v:
Internat. J. Math. 25 (2014), no.7
Bernardi and Tirabassi show the existence of full strong exceptional collections consisting of line bundles on smooth toric Fano $3$-folds under assuming Bondal's conjecture, which states that the Frobenius push-forward of the structure sheaf $\mc O_
Externí odkaz:
http://arxiv.org/abs/1012.4086