Zobrazeno 1 - 10
of 61
pro vyhledávání: '"Seppänen, Henrik"'
Autor:
Maslovarić, Marcel, Seppänen, Henrik
We generalize the notion of multi-Gieseker semistability for coherent sheaves, introduced by Greb, Ross, and Toma, to quiver sheaves for a quiver $Q$. We construct coarse moduli spaces for semistable quiver sheaves using a functorial method that real
Externí odkaz:
http://arxiv.org/abs/1710.00371
Autor:
Pezzini, Guido, Seppänen, Henrik
We define and study the global Okounkov moment cone of a projective spherical variety X, generalizing both the global Okounkov body and the moment body of X defined by Kaveh and Khovanskii. Under mild assumptions on X we show that the global Okounkov
Externí odkaz:
http://arxiv.org/abs/1709.10162
We prove that on a Bott-Samelson variety $X$ every movable divisor is nef. This enables us to consider Zariski decompositions of effective divisors, which in turn yields a description of the Mori chamber decomposition of the effective cone. This amou
Externí odkaz:
http://arxiv.org/abs/1709.09910
Autor:
Seppänen, Henrik, Tsanov, Valdemar V.
We consider the action of a semisimple subgroup $\hat G$ of a semisimple complex group $G$ on the flag variety $X=G/B$, and the linearizations of this action by line bundles $\mathcal L$ on $X$. The main result is an explicit description of the assoc
Externí odkaz:
http://arxiv.org/abs/1607.04231
Autor:
Seppänen, Henrik, Tsanov, Valdemar V.
Let G be a semisimple complex Lie group. In this article, we study Geometric Invariant Theory on a flag variety G/B with respect to the action of a principal 3-dimensional simple subgroup S of G. We determine explicitly the GIT-equivalence classes of
Externí odkaz:
http://arxiv.org/abs/1503.07105
Autor:
Seppänen, Henrik
Let $G'$ be a complex semisimple group, and let $G \subseteq G'$ be a semisimple subgroup. We show that the branching cone of the pair $(G, G')$, which (asymptotically) parametrizes all pairs $(W, V)$ of irreducible finite-dimensional $G$-representat
Externí odkaz:
http://arxiv.org/abs/1409.2025
Okounkov bodies for ample line bundles with applications to multiplicities for group representations
Autor:
Seppänen, Henrik
Let $\mathscr{L} \rightarrow X$ be an ample line bundle over a complex normal projective variety $X$. We construct a flag $X_0 \subseteq X_1 \subseteq \cdots \subseteq X_n=X$ of subvarieties for which the associated Okounkov body for $\mathscr{L}$ is
Externí odkaz:
http://arxiv.org/abs/1409.2026
Autor:
Schmitz, David, Seppänen, Henrik
We use the theory of Mori dream spaces to prove that the global Okounkov body of a Bott-Samelson variety with respect to a natural flag of subvarieties is rational polyhedral. In fact, we prove more generally that this holds for any Mori dream space
Externí odkaz:
http://arxiv.org/abs/1409.1857
Autor:
Schmitz, David, Seppänen, Henrik
We prove that the existence of a finite Minkowski base for Okounkov bodies on a smooth projective variety with respect to an admissible flag implies rational polyhedrality of the global Okounkov body. As an application of this general result, we dedu
Externí odkaz:
http://arxiv.org/abs/1403.4517
Autor:
Schwarz, Benjamin, Seppänen, Henrik
Let $G$ be a complex simple Lie group, and let $U \subseteq G$ be a maximal compact subgroup. Assume that $G$ admits a homogenous space $X=G/Q=U/K$ which is a compact Hermitian symmetric space. Let $\mathscr{L} \rightarrow X$ be the ample line bundle
Externí odkaz:
http://arxiv.org/abs/1110.6324