Zobrazeno 1 - 10
of 169
pro vyhledávání: '"Hausen, Jürgen"'
Autor:
Hausen, Jürgen, Király, Katharina
We give an explicit description of all quasismooth, rational, projective surfaces of Picard number one that admit a non-trivial torus action and have an integral canonical self intersection number.
Comment: 38 pages
Comment: 38 pages
Externí odkaz:
http://arxiv.org/abs/2411.15079
The Markov triples, that means the positive integer solutions of the equation $x^2+y^2+z^2=3xyz$, form the vertex set of the Markov tree. Each Markov triple defines a weighted projective plane, which gives a geometric interpretation of the vertex. We
Externí odkaz:
http://arxiv.org/abs/2405.04862
Autor:
Hausen, Jürgen, Király, Katharina
A full intrinsic quadric is a normal complete variety with a finitely generated Cox ring defined by a single quadratic relation of full rank. We describe all surfaces of this type explicitly via local Gorenstein indices. As applications, we present u
Externí odkaz:
http://arxiv.org/abs/2310.08293
We consider two classes of non-toric log del Pezzo $\mathbb{C}^*$-surfaces: on the one side the 1/3-log canonical ones and on the other side those of Picard number one and Gorenstein index at most 65. In each of the two classes we figure out the surf
Externí odkaz:
http://arxiv.org/abs/2306.03796
We consider log del Pezzo surfaces coming with a non-trivial torus action. Such a surface is 1/k-log canonical if it allows a resolution of singularities with discrepanies all greater or equal to 1/k-1. We provide a concrete classification algorithm
Externí odkaz:
http://arxiv.org/abs/2302.03095
We present efficient classification algorithms for log del Pezzo surfaces with torus action of Picard number one and given Gorenstein index. Explicit results are obtained up to Gorenstein index 200.
Comment: 29 pages
Comment: 29 pages
Externí odkaz:
http://arxiv.org/abs/2207.14790
Autor:
Bäuerle, Andreas, Hausen, Jürgen
Publikováno v:
SIGMA 18 (2022), 088, 42 pages
We classify the non-toric, $\mathbb Q$-factorial, Gorenstein, log terminal Fano threefolds of Picard number one that admit an effective action of a two-dimensional algebraic torus.
Externí odkaz:
http://arxiv.org/abs/2108.03029
Autor:
Hausen, Juergen, Hummel, Timo
We consider possibly singular rational projective k*-surfaces and provide an explicit description of the unit component of the automorphism group in terms of isotropy group orders and intersection numbers of suitable invariant curves. As an applicati
Externí odkaz:
http://arxiv.org/abs/2010.06414
The anticanonical complex generalizes the Fano polytope from toric geometry and has been used to study Fano varieties with torus action so far. We work out the case of complete intersections in toric varieties defined by non-degenerate systems of Lau
Externí odkaz:
http://arxiv.org/abs/2006.04723
We classify the smooth Fano 4-folds of Picard number two that have a general hypersurface Cox ring.
Comment: 35 pages, new results added, to appear in Rev. Mat. Iberoam
Comment: 35 pages, new results added, to appear in Rev. Mat. Iberoam
Externí odkaz:
http://arxiv.org/abs/1907.08000