Search results for "Varie"

Special Families of Curves, of Abelian Varieties, and of Certain Minimal Manifolds over Curves

2006

This survey article discusses some results on the structure of families f:V-->U of n-dimensional manifolds over quasi-projective curves U, with semistable reduction over a compactification Y of U. We improve the Arakelov inequality for the direct images of powers of the dualizing sheaf. For families of Abelian varieties we recall the characterization of Shimura curves by Arakelov equalities. For families of curves we recall the characterization of Teichmueller curves in terms of the existence of certain sub variation of Hodge structures. We sketch the proof that the moduli scheme of curves of genus g>1 can not contain compact Shimura curves, and that it only contains a non-compact Shimura c…

Quasi-Projective Varieties

2000

We have developed the theory of affine and projective varieties separately. We now introduce the concept of a quasi-projective variety, a term that encompasses both cases. More than just a convenience, the notion of a quasi-projective variety will eventually allow us to think of an algebraic variety as an intrinsically defined geometric object, free from any particular embedding in affine or projective space.

On P-compatible hybrid identities and hyperidentities

1994

P-compatible identities are built up from terms with a special structure. We investigate a variety defined by a set ofP-compatible hybrid identities and answer the question whether a variety defined by a set ofP-compatible hyperidentities can be solid.

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 divisors define free quotients, whereas ℚ–Cartier divisors define geometric quotients. Each quotient presentation yields homogeneous coordinates. Using homogeneous coordinates, we express quasicoherent sheaves in terms of multigraded modules and describe the set of morphisms into a toric variety.

On many-sorted algebraic closure operators

2004

A theorem of Birkhoff-Frink asserts that every algebraic closure operator on an ordinary set arises, from some algebraic structure on the set, as the corresponding generated subalgebra operator. However, for many-sorted sets, i.e., indexed families of sets, such a theorem is not longer true without qualification. We characterize the corresponding many-sorted closure operators as precisely the uniform algebraic operators. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Asymptotically good codes from generalized algebraic-geometry codes

2005

We consider generalized algebraic-geometry codes, based on places of the same degree of a fixed algebraic function field over a finite field. In this note, using a method similar to the Justesen's one, we construct a family of such codes which is asymptotically good.

ON AUTOMORPHISMS OF GENERALIZED ALGEBRAIC-GEOMETRY CODES.

2007

Abstract We consider a class of generalized algebraic-geometry codes based on places of the same degree of a fixed algebraic function field over a finite field F / F q . We study automorphisms of such codes which are associated with automorphisms of F / F q .

A complete variety with infinitely many maximal quasi-projective open subsets. (English summary)

2010

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Bearing gods in mind and culture

2011

Abstract Where do supernatural agents come from and why do they stay around? Within the biocultural study of religion one finds a growing tendency to answer these questions by weaving together two conceptual threads, which I will refer to as anthropomorphic promiscuity and sociographic prudery. Although descriptions of these theogonic (god-bearing) mechanisms can differ significantly, the theoretical pattern can be recognized in authors from a variety of disciplines. I illustrate this pattern using four books published in 2010: David Lewis-Williams's Conceiving God: The Cognitive Origin and Evolution of Religion, Pascal Boyer's The Fracture of an Illusion: Science and the Dissolution of Rel…

HPLC-DAD profile of phenolic compounds and In vitro antioxidant activity of Ficus carica L. fruits from two Algerian varieties

2022

Ficus carica L., commonly known as the fig tree, is a plant belonging to the Moraceae family whose fruits are traditionally used for edible and therapeutic purposes. The study aimed to investigate the lyophilized aqueous extracts of two native Algerian fig varieties, azendjar (Az) and taamriouth (Ta), as a potential source of antioxidant compounds for possible use as ingredients in pharmaceuticals or nutraceuticals. The HPLC-DAD analysis revealed the presence of two phenolic acids (3,4-dihydroxybenzoic acid and vanillic acid) and two flavonoids (rutin and quercetin) at levels 3.67, 4.80, 84.16, and 6.87 µg/g respectively for Az variety extract, and 6.90, traces, 7.46 and 3.37 µg/g respectiv…