All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 2 Next

Displaying 21 – 40 of 88

Showing per page

A new proof of desingularization over fields of characteristic zero.

Santiago Encinas, Orlando Villamayor (2003)

Revista Matemática Iberoamericana

We present a proof of embedded desingularization for closed subschemes which does not make use of Hilbert-Samuel function and avoids Hironaka's notion of normal flatness (see also [171 page 224). Given a subscheme defined by equations, we prove that embedded desingularization can be achieved by a sequence of monoidal transformations; where the law of transformation on the equations defining the subscheme is simpler then that used in Hironaka 's procedure. This is done by showing that desingularization...

A note on a theorem of Horikawa.

Francesco Zucconi (1997)

Revista Matemática de la Universidad Complutense de Madrid

In this paper we classify the algebraic surfaces on C with KS2=4, pg=3 and canonical map of degree d=3. By our result and the previous one of Horikawa (1979) we obtain the complete determination of surfaces with K2=4 and pg=3.

A problem of Kollár and Larsen on finite linear groups and crepant resolutions

Robert Guralnick, Pham Tiep (2012)

Journal of the European Mathematical Society

The notion of age of elements of complex linear groups was introduced by M. Reid and is of importance in algebraic geometry, in particular in the study of crepant resolutions and of quotients of Calabi–Yau varieties. In this paper, we solve a problem raised by J. Kollár and M. Larsen on the structure of finite irreducible linear groups generated by elements of age ≤ 1 . More generally, we bound the dimension of finite irreducible linear groups generated by elements of bounded deviation. As a consequence...

A propos du problème des arcs de Nash

Camille Plénat (2005)

Annales de l’institut Fourier

Soit ℋ = ⋃ N i la décomposition canonique de l’espace des arcs ℋ passant par une singularité normale de surface. Dans cet article, on propose deux nouvelles conditions qui si elles sont vérifiées permettent de montrer que N i n’est pas inclus dans N j . On applique ces conditions pour donner deux nouvelles preuves du problème de Nash pour les singularités sandwich minimales.

A set on which the Łojasiewicz exponent at infinity is attained

Jacek Chądzyński, Tadeusz Krasiński (1997)

Annales Polonici Mathematici

We show that for a polynomial mapping F = ( f ₁ , . . . , f ₘ ) : ℂ n → ℂ m the Łojasiewicz exponent ∞ ( F ) of F is attained on the set z ∈ ℂ n : f ₁ ( z ) · . . . · f ₘ ( z ) = 0 .

A simpler proof of toroidalization of morphisms from 3-folds to surfaces

Steven Dale Cutkosky (2013)

Annales de l’institut Fourier

We give a simpler and more conceptual proof of toroidalization of morphisms of 3-folds to surfaces, over an algebraically closed field of characteristic zero. A toroidalization is obtained by performing sequences of blow ups of nonsingular subvarieties above the domain and range, to make a morphism toroidal. The original proof of toroidalization of morphisms of 3-folds to surfaces is much more complicated.

A simplified proof of desingularization and applications.

Ana María Bravo, Santiago Encinas, Orlando Villamayor Uriburu (2005)

Revista Matemática Iberoamericana

This paper contains a short and simplified proof of desingularization over fields of characteristic zero, together with various applications to other problems in algebraic geometry (among others, the study of the behavior of desingularization of families of embedded schemes, and a formulation of desingularization which is stronger than Hironaka's). Our proof avoids the use of the Hilbert-Samuel function and Hironaka's notion of normal flatness: First we define a procedure for principalization of...

A Smooth Four-Dimensional G-Hilbert Scheme

Sebestean, Magda (2004)

Serdica Mathematical Journal

2000 Mathematics Subject Classification: 14C05, 14L30, 14E15, 14J35.When the cyclic group G of order 15 acts with some specific weights on affine four-dimensional space, the G-Hilbert scheme is a crepant resolution of the quotient A^4 / G. We give an explicit description of this resolution using G-graphs.

Currently displaying 21 – 40 of 88