Browsing Τμήμα Μαθηματικών και Στατιστικής / Department of Mathematics and Statistics by Author "Tziolas, Nikolaos"
Now showing items 1-15 of 15
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Automorphisms of smooth canonically polarized surfaces in positive characteristic
Tziolas, Nikolaos (2017)This paper investigates the geometry of a smooth canonically polarized surface X defined over an algebraically closed field of characteristic p>0 in the case when the automorphism scheme of X is not smooth. In particular, ...
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Corrigendum to “Automorphisms of smooth canonically polarized surfaces in positive characteristic” Adv. Math. 310 (2017) 235–289
Tziolas, Nikolaos (2018)This note corrects some mistakes in the proof of Theorem 6.5 in my paper Automorphism of smooth canonically polarized surfaces in positive characteristic which was published by Tziolas (2017) [2].
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Erratum: Families of D-minimal models and applications to 3-fold divisorial contractions (Proceedings of the London Mathematical Society (2005) 90:3 (345-370))
Tziolas, Nikolaos (2006)
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Families of D-minimal models and applications to 3-fold divisorial contractions
Tziolas, Nikolaos (2005)
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First order deformations of schemes with normal crossing singularities
Tziolas, Nikolaos (2011)We study the sheaf T1(X) of first order deformations of a reduced scheme with normal crossing singularities. In particular, we obtain a formula for T1(X) in a suitable log resolution of X. © 2011 Springer-Verlag.
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Infinitesimal extensions of ℙ1 and their Hilbert Schemes
Tziolas, Nikolaos (2002)In order to calculate the multiplicity of an isolated rational curve C on a local complete intersection variety X, i.e. the length of the local ring of the Hilbert Scheme of X at [C], it is important to study infinitesimal ...
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Multiplicities of smooth rational curves on singular local complete intersection Calabi-Yau threefolds
Tziolas, Nikolaos (2001)We study deformations of smooth rational curves on singular varieties. We define the multiplicity of an isolated rational curve on a local complete intersection Calabi-Yau threefold. We show that it varies "well" in families ...
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Quotients of schemes by αp or μp actions in characteristic p> 0
Tziolas, Nikolaos (2017)This paper studies integral schemes X defined over a field of characteristic p> 0 which admit a nontrivial αp or μp action. In particular, the quotient map X→ Y is investigated and structure theorems for it are obtained. ...
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Smoothings of Fano Varieties with Normal Crossing Singularities
Tziolas, Nikolaos (2015)This paper obtains criteria for a Fano variety X defined over an algebraically closed field of characteristic zero with normal crossing singularities to be smoothable. In particular, we show that X is smoothable by a flat ...
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Smoothings of Fano Varieties With Normal Crossing Singularities[ONLINE]
Tziolas, Nikolaos (2015)
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Smoothings of schemes with nonisolated singularities
Tziolas, Nikolaos (2010)
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Terminal 3-fold divisorial contractions of a surface to a curve I
Tziolas, Nikolaos (2004)Let Γ ⊂ X be a smooth curve on a 3-fold which has only index 1 terminal singularities along Γ. In this paper we investigate the existence of extremal terminal divisorial contractions E ⊂ Y → ⊂ X, contracting an irreducible ...
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Three dimensional divisorial extremal neighborhoods
Tziolas, Nikolaos (2005)In this paper we study divisorial extremal neighborhoods [InlineMediaObject not available: see fulltext.] such that 0 X is a cA n type threefold terminal singularity, and Γ=f(E) is a smooth curve, where E is the f-exceptional ...
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Three-fold divisorial extremal neighborhoods over cE7 and cE6 compound duval singularities
Tziolas, Nikolaos (2010)Let P ∈ Γ ⊂ X be the germ of a Gorenstein three-fold singularity and Γ a smooth curve through it such that the general hyperplane section S of X containing Γ is DuVal of type E6 or E7. In this paper we obtain criteria for ...
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ℚ-gorenstein deformations of nonnormal surfaces
Tziolas, Nikolaos (2009)Let Δ C H be the germ of a nonnormal surface along a proper curve with smooth components such that the high index points of H are semi-log-terminal and the Gorenstein singular points are semi-log-canonical of embedding ...