Zobrazeno 1 - 10
of 23
pro vyhledávání: '"Purnaprajna, B. P."'
Autor:
Gallego, F. J., Purnaprajna, B. P.
In this article we study the bicanonical map $\phi_2$ of quadruple Galois canonical covers X of surfaces of minimal degree. We show that $\phi_2$ has diverse behavior and exhibit most of the complexities that are possible for a bicanonical map of sur
Externí odkaz:
http://arxiv.org/abs/1001.1128
In this article we study the deformation of finite maps and show how to use this deformation theory to construct varieties with given invariants in a projective space. Among other things, we prove a criterion that determines when a finite map can be
Externí odkaz:
http://arxiv.org/abs/1001.1081
In this article we classify quadruple Galois canonical covers of smooth surfaces of minimal degree. The classification shows that they are either non-simple cyclic covers or bi-double covers. If they are bi-double then they are all fiber products of
Externí odkaz:
http://arxiv.org/abs/math/0302045
Let f be a generically finite morphism from X to Y. The purpose of this paper is to show how the O_Y algebra structure on the push forward of O_X controls algebro-geometric aspects of X like the ring generation of graded rings associated to X and the
Externí odkaz:
http://arxiv.org/abs/math/0111052
The goal of this article is to study the equations and syzygies of embeddings of rational surfaces and certain Fano varieties. Given a rational surface X and an ample and base-point-free line bundle L on X, we give an optimal numerical criterion for
Externí odkaz:
http://arxiv.org/abs/math/0001107
Autor:
Gallego, F. J., Purnaprajna, B. P.
This work consists of two parts. In the first part we develop new techniques to compute Koszul cohomology groups for several classes of varieties. As applications we prove results on projective normality and syzygies for algebraic surfaces. From more
Externí odkaz:
http://arxiv.org/abs/alg-geom/9703036
Autor:
Gallego, F. J., Purnaprajna, B. P.
In this article we prove some strong vanishing theorems on K3 surfaces. As an aplication of them, we obtain higher syzygy results for K3 surfaces and Fano varieties.
Comment: AMS-TeX
Comment: AMS-TeX
Externí odkaz:
http://arxiv.org/abs/alg-geom/9608008
Autor:
Gallego, Francisco, Purnaprajna, B. P.
Let L be a normally generated line bundle on X; we say L satisfies property N_p (notation after Mark Green) if the matrices in the free resolution of R (the homogeneous coordinate ring of X) over S (the homogeneous coordinate ring of the projective s
Externí odkaz:
http://arxiv.org/abs/alg-geom/9512005
Autor:
Gallego, Francisco, Purnaprajna, B. P.
A ribbon D over a variety C is a scheme such that D_{red} = C, the ideal I in O_D of Cis a line bundle on C and I^2 = 0. A two dimensional ribbon is called a carpet. In this article we show that if D is a K3 carpet, that is a ribbon associated to a r
Externí odkaz:
http://arxiv.org/abs/alg-geom/9511014
Autor:
Gallego, Francisco, Purnaprajna, B. P.
In this article we determine exactly which line bundles on elliptic ruled surface X are normally presented. In particular we see that numerical classes of normally presented divisors form a convex set. (recall that Num(X) is generated by the class of
Externí odkaz:
http://arxiv.org/abs/alg-geom/9511013