Zobrazeno 1 - 10
of 219
pro vyhledávání: '"Hausen, J."'
Publikováno v:
J. Algebra, 387, 87-98, 2013
Given an action of an affine algebraic group with only trivial characters on a factorial variety, we ask for categorical quotients. We characterize existence in the category of algebraic varieties. Moreover, allowing constructible sets as quotients,
Externí odkaz:
http://arxiv.org/abs/0908.0443
Autor:
A'Campo-Neuen, A., Hausen, J.
Publikováno v:
Result. Math. 43, 13-22 (2003)
Consider an algebraic torus of small dimension acting on an open subset of a complex vector space, or more generally on a quasiaffine variety such that a separated orbit space exists. We discuss under which conditions this orbit space is quasiproject
Externí odkaz:
http://arxiv.org/abs/math/0110133
Publikováno v:
Math. Nachr. 246-247, 5-19 (2002)
Generalizing cones over projective toric varieties, we present arbitrary toric varieties as quotients of quasiaffine toric varieties. Such quotient presentations correspond to groups of Weil divisors generating the topology. Groups comprising Cartier
Externí odkaz:
http://arxiv.org/abs/math/0005083
Autor:
A'Campo-Neuen, A., Hausen, J.
Publikováno v:
J. Algebra 231, 67-85 (2000)
We give examples for existence and non-existence of categorical quotients for algebraic group actions in the categories of algebraic varieties and prevarieties. All our examples are subtorus actions on toric varieties.
Comment: 15 pages, 3 figur
Comment: 15 pages, 3 figur
Externí odkaz:
http://arxiv.org/abs/math/0002096
Autor:
Hausen, J., Schroeer, S.
Publikováno v:
Proc. Amer. Math. Soc. 132, 681-685 (2004)
What kind of schemes are embeddable into good toric prevarieties? To shed some light on this question, we construct proper normal surfaces that are embeddable into neither simplicial toric prevarieties nor toric prevarieties of affine intersection.
Externí odkaz:
http://arxiv.org/abs/math/0002046
Autor:
A'Campo-Neuen, A., Hausen, J.
Publikováno v:
Michigan Math. J. 50, No 1., 101-123 (2002)
We consider subtorus actions on divisorial toric varieties. Here divisoriality means that the variety has many Cartier divisors like quasiprojective and smooth ones. We characterize when a subtorus action on such a toric variety admits a categorical
Externí odkaz:
http://arxiv.org/abs/math/0001131
Autor:
A'Campo-Neuen, A., Hausen, J.
Publikováno v:
Geometriae Dedicata 87, 35-64 (2001)
Dropping separatedness in the definition of a toric variety, one obtains the more general notion of a toric prevariety. Toric prevarieties occur as ambient spaces in algebraic geometry and moreover they appear naturally as intermediate steps in quoti
Externí odkaz:
http://arxiv.org/abs/math/9912229
Autor:
Hausen, J., Schröer, S.
Publikováno v:
Proceedings of the American Mathematical Society, 2004 Mar 01. 132(3), 681-685.
Externí odkaz:
https://www.jstor.org/stable/1194684
Autor:
A'Campo-Neuen, A., Hausen, J.
Publikováno v:
Tohoku Math. J. 51 (1999), 1-12.
We consider the action of a subtorus of the big torus on a toric variety. The aim of the paper is to define a natural notion of a quotient for this setting and to give an explicit algorithm for the construction of this quotient from the combinatorial
Externí odkaz:
http://arxiv.org/abs/math/9806049
Autor:
Hausen, J., Heinzner, P.
Publikováno v:
Transformation Groups, Vol. 4, No.1, 25-34 (1999)
Let K be a compact Lie group and G its complexification. For a not necessarily reduced Stein K-space X we show that there is a complex space Z endowed with a holomorphic action of the universal complexification G of K that contains X as an open K-sta
Externí odkaz:
http://arxiv.org/abs/math/9805138