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One of the most attractive problems in algebraic geometry is Hartshorne’s conjecture ([9]): ”let X ⊂ P(C) be a smooth subvariety, if dim(X) > 2 3 n then X is a complete intersection”. Due to the connection with the existence of rank two vector bundles, the codimension two case is particularly interesting. Thanks to Barth’s result ([2]) and since no(More)
Several observed anomalies in neutrino oscillation data can be explained by a hypothetical fourth neutrino separated from the three standard neutrinos by a squared mass difference of a few eV(2). We show that this hypothesis can be tested with a PBq (ten kilocurie scale) (144)Ce or (106)Ru antineutrino beta source deployed at the center of a large low(More)
Our main theorem characterizes the complete intersections of codimension 2 in a projective space of dimension 3 or more over an algebraically closed field of characteristic 0 as the subcanonical and self-linked subschemes. In order to prove this theorem, we’ll prove the Gherardelli linkage theorem, which asserts that a partial intersection of two(More)
The Cell Design System (CDS) is part of a set of tools developed in the 1970s by the Electronics Division of Xerox to support CAD design. This paper describes the CDS, which is a highly interactive graphics system used for layout of custom chips. Described are the hardware environment and language, the kinds of manipulation allowed, types of objects, and(More)
In the classification of smooth codimension two subvarieties of P, surfaces in P (resp. threefolds in P) seem to lie between two extremal situations: every curve can be embedded in P while, according to Hartshorne’s conjecture, every smooth, codimension two subvariety of P, n ≥ 6, should be a complete intersection. As well known, not every surface can be(More)
For a projective variety Z and for any integer p, define the p-th Néron-Severi group NSp(Z) of Z as the image of the cycle map Ap(Z) → H2p(Z;C). Now let X ⊂ P (m ≥ 1) be a projective variety of dimension 2m − 1, with isolated singularities, complete intersection of a smooth hypersurface of degree k, with a hypersurface of degree n > max{k, 2m + 1}, and let(More)
where Cliff(L) := deg(L)− 2(h0(L)− 1) (see for example [CM] and [ELMS]). In the first section of this paper we consider subcanonical curves in P. Let C ⊂ P and let Γ be a point set computing the gonality of C. If l ≥ 2 represents the maximum degree of a zero-dimensional subscheme of C which is contained in a line, then d := Gon(C) = d(Γ) ≤ d(C)− l. If(More)
Exposure to environmental odour can result in annoyance, health effects and depreciation of property values. Therefore, many jurisdictions classify odour as an atmospheric pollutant and regulate emissions and/or impacts from odour generating activities at a national, state or municipal level. In this work, a critical review of odour regulations in selected(More)