Browsing Mathematics and Computer Studies (Peerreviewed publications) by Title
Now showing items 2840 of 40

On semistable vector bundles over curves (Prepublished version)
(Elsevier, 2008)Let X be a geometrically irreducible smooth projective curve de ned over a eld k, and let E be a vector bundle on X. Then E is semistable if and only if there is a vector bundle F on X such that Hi(X; F E) = 0 for i = 0; ... 
The Picard group of a coarse moduli space of vector bundles in positive characteristic (Prepublished version)
(Versita, copublished with Springer Verlag., 2012)Let C be a smooth projective curve over an algebraically closed field of arbitrary characteristic. Let Mss r,L denote the projective coarse moduli scheme of semistable rank r vector bundles over C with fixed determinant ... 
Poincaré families and automorphisms of principal bundles on a curve (Prepublished version)
(Elsevier, 2009)Let C be a smooth projective curve, and let G be a reductive algebraic group. We give a necessary condition, in terms of automorphism groups of principal Gbundles on C, for the existence of Poincaré families parameterized ... 
Poincaré families of Gbundles on a curve (Prepublished version)
(Springer Verlag, 2012)Let G be a reductive group over an algebraically closed ﬁeld k. Consider the moduli space of stable principal Gbundles on a smooth projective curve C over k. We give necessary and suﬃcient conditions for the existence of ... 
Rationality and Poincaré families for vector bundles with extra structure on a curve (Prepublished version)
(Oxford University Press, 2007)Iterated Grassmannian bundles over moduli stacks of vector bundles on a curve are shown to be birational to an affine space times a moduli stack of degree 0 vector bundles, following the method of King and Schofield. ... 
Response surface designs using the generalized variance inflation factors
(Cogent OA, 2015)We study response surface designs using the generalized variance inflation factors for subsets as an extension of the variance inflation factors. 
Solving cubic equations in two variables
(Irish Mathematical Society, 2007)After recalling a geometric construction of all Pythagorean triples of integers, the same idea is applied to find rational solutions of cubic equations in two variables. This leads to the definition of the MordellWeil ... 
Some moduli stacks of symplectic bundles on a curve are rational (Prepublished version)
(Elsevier, 2008)Let C be a smooth projective curve of genus g ≥ 2 over a ﬁeld k. Given a line bundle L on C, let Sympl2n,L be the moduli stack of vector bundles E of rank 2n on C endowed with a nowhere degenerate symplectic form b : E ⊗ ... 
Stability of Arakelov bundles and tensor products without global sections
(Documenta Mathematica, 2003)This paper deals with Arakelov vector bundles over an arithmetic curve, i.e. over the set of places of a number field. The main result is that for each semistable bundle E, there is a bundle F such that E⊗F has at least ... 
SU(5) heterotic standard model bundles (Prepublished version)
(Springer Verlag, 2012)We construct a class of stable SU(5) bundles on an elliptically ﬁbered CalabiYau threefold with two sections, a variant of the ordinary Weierstrass ﬁbration, which admits a free involution. The bundles are invariant under ... 
Torelli theorem for the DeligneHitchin moduli space (Prepublished version)
(Springer Verlag, 2009)Fix integers g ≥ 3 and r ≥ 2, with r ≥ 3 if g = 3. Given a compact connected Riemann surface X of genus g, let M DH (X) denote the corresponding SL(r,C) Deligne–Hitchin moduli space. We prove that the complex analytic ... 
Trace forms of symbol algebras (Prepublished version)
(World Scientific Publishing Complany, 2012)Let S be a symbol algebra. The trace form of S is computed and it is shown how this form can be used to determine whether S is a division algebra or not. In addition, the exterior powers of the trace form of S are computed. 
Twistor spaces with a pencil of fundamental divisors
(Documenta Mathematica, 1999)In this paper simply connected twistor spaces Z containing a pencil of fundamental divisors are studied. The Riemannian base for such spaces is diffeomorphic to the connected sum nCP2 . We obtain for n 5 a complete ...