Browsing Mathematics and Computer Studies (Peerreviewed publications) by Title
Now showing items 827 of 40

EinsteinHermitian connection on twisted Higgs bundles (Prepublished Version)
(Elsevier Masson, 2010)Let X be a smooth projective variety over C. We prove that a twisted Higgs vector bundle (E , θ) on X admits an Einstein–Hermitian connection if and only if (E , θ) is polystable. A similar result for twisted vector bundles ... 
Elliptic curves – an introduction
(Irish Mathematical Society, 2007) 
Existence of twistor spaces of algebraic dimension two over the connected sum of four complex projective planes
(American Mathematical Society, 1999)We prove the existence of twistor spaces of algebraic dimension two over the connected sum of four complex projective planes 4CP2. These are the rst examples of twistor spaces of algebraic dimension two over a ... 
Generalized vector bundles on curves (Prepublished version)
(de Gruyter, 1998)In their paper [14] G. Harder and M.S. Narasimhan (and independently D. Quillen) have constructed a canonical flag of subbundles on any vector bundle on a complete smooth algebraic curve over a field. This flag measures ... 
Geometric view of measurement errors
(Taylor and Francis, 2011)The slope of the best fit line from minimizing the sum of the squared oblique errors is the root of a polynomial of degree four. This geometric view of measurement errors is used to give insight into the performance of ... 
Homological algebra with locally compact abelian groups (Prepublished Version)
(Elsevier, 2007)In this article we study locally compact abelian (LCA) groups from the viewpoint of derived categories, using that their category is quasiabelian in the sense of J.P. Schneiders. We deﬁne a wellbehaved derived Homcomplex ... 
Independent parameters for special instanton bundles on P^{2n+1} (Prepublished Version)
(Elsevier, 2011)Motivated by YangMills theory in 4n dimensions, and generalizing the notion due to Atiyah, Drinfeld, Hitchin and Manin for n = 1, Okonek, Spindler and Trautmann introduced instanton bundles and special instanton bundles ... 
An investigation of the performance of five different estimators in the measurement error regression model
(Athens Institute for Education and Research, 2015)In a comprehensive paper by Riggs et al.(1978) the authors analyse the performances of numerous estimators for the regression slope in the measurement error model with positive measurement error variances >0 0 for X and ... 
Ireland's participation in the 50th international mathematical olympiad
(Irish Mathematical Society, 2009)The 50th International Mathematical Olympiad (IMO) took place in Bremen (Germany) from 12th July until 22nd July 2009. With 565 participants (59 of whom were girls) from 104 countries, this was the IMO with the largest ... 
The line on moduli stacks of principal bundles on a curve
(Documenta Mathematica, 2010)Let G be an affine reductive algebraic group over an algebraically closed field k. We determine the Picard group of the moduli stacks of principal G–bundles on any smooth projective curve over k. 
Minimizing oblique errors for robust estimating
(Irish Mathematical Society, 2008)The slope of the best fit line from minimizing the sum of the squared oblique errors is shown to be the root of a polynomial of degree four. We introduce a median estimator for the slope and, using a case study, we show ... 
Mitigating collinearity in linear regression models using ridge, surrogate and raised estimators
(Cogent OA, 2016)Collinearity in the design matrix is a frequent problem in linear regression models, for example, with economic or medical data. Previous standard procedures to mitigate the effects of collinearity included ridge regression ... 
Moduli schemes of generically simple Azumaya modules
(Documenta Mathematica, 2005)Let A be an Azumaya algebra over a smooth projective variety X or more generally, a torsion free coherent sheaf of algebras over X whose generic fiber is a central simple algebra. We show that generically simple torsion ... 
The moduli stack of vector bundles on a curve (Prepublished Version)
(Ramanujan Mathematical Society, 2010)This expository text tries to explain brie y and not too technically the notions of stack and algebraic stack, emphasizing as an example the moduli stack of vector bundles on an algebraic curve. 
Moduli stacks of vector bundles on curves and the King–Schofield rationality proof (Prepublished version)
(Springer, 2010)Let C be a connected smooth projective curve of genus g ≥ 2 over an algebraically closed field k. Consider the coarse moduli scheme Bunr,d (resp. Bunr,L) of stable vector bundles on C with rank r and degree d ∈ Z (resp. ... 
Moishezon twistor spaces without effective divisors of degree one (prepublished version)
(Universität Kaiserslautern, 1995)We study simply connected compact twistor spaces Z of positive type. Assuming that the fundamental linear system j \Gamma 1 2 Kj is at least a pencil, we prove the following theorem: the existence of an irreducible curve ... 
New examples of stable bundles on CalabiYau threefolds (Prepublished Version)
(Oxford University Press, 2012)In this paper we present a construction of stable bundles on CalabiYau threefolds using the method of bundle extensions. This construction applies to any given CalabiYau threefold with h1 , 1 > 1. We give examples ... 
A note on the computation of symmetric powers of hyperbolic forms and of trace froms on symbol algebras
(Scientific Advances Publishers, 2014)Let K be a field with characteristic different from 2 and let S be a symbol algebra over K. We compute the symmetric powers of hyperbolic quadratic forms over K. Also, we compute the symmetric powers of the quadratic trace ... 
On a relative FourierMukai transform on genus one fibrations
(Springer, 2006)We study relative FourierMukai transforms on genus one fibrations with section, allowing explicitly the total space of the fibration to be singular and nonprojective. Grothendieck duality is used to prove a ... 
On moduli stacks of Gbundles over a curve (Prepublished version)
(Springer, 2010)Let C be a smooth projective curve over an algebraically closed eld k of arbitrary characteristic. Given a linear algebraic group G over k, let MG be the moduli stack of principal Gbundles on C. We determine the set of ...