Search results for "Crete"
showing 10 items of 2495 documents
On the product of a nilpotent group and a group with non-trivial center
2007
Abstract It is proved that a finite group G = A B which is a product of a nilpotent subgroup A and a subgroup B with non-trivial center contains a non-trivial abelian normal subgroup.
Characters of relative p'-degree over normal subgroups
2013
Let Z be a normal subgroup of a finite group G , let ??Irr(Z) be an irreducible complex character of Z , and let p be a prime number. If p does not divide the integers ?(1)/?(1) for all ??Irr(G) lying over ? , then we prove that the Sylow p -subgroups of G/Z are abelian. This theorem, which generalizes the Gluck-Wolf Theorem to arbitrary finite groups, is one of the principal obstacles to proving the celebrated Brauer Height Zero Conjecture
A Characterization of the Class of Finite Groups with Nilpotent Derived Subgroup
2002
The class of all finite groups with nilpotent commutator subgroup is characterized as the largest subgroup-closed saturated formation đ for which the đ-residual of a group generated by two đ-subnormal subgroups is the subgroup generated by their đâresiduals.
On fully ramified Brauer characters
2014
Let Z be a normal subgroup of a finite group, let pâ 5 be a prime and let λâIBr(Z) be an irreducible G-invariant p-Brauer character of Z. Suppose that λG=eÏ for some ÏâIBr(G). Then G/Z is solvable. In other words, a twisted group algebra over an algebraically closed field of characteristic not 5 with a unique class of simple modules comes from a solvable group.
Normalities and Commutators
2010
We first compare several algebraic notions of normality, from a categorical viewpoint. Then we introduce an intrinsic description of Higgins' commutator for ideal-determined categories, and we define a new notion of normality in terms of this commutator. Our main result is to extend to any semi-abelian category the following well-known characterization of normal subgroups: a subobject K is normal in A if. and only if, {[A, K] <= K. (C) 2010 Elsevier Inc. All rights reserved.}
The measuring method for tests of horizontal two-phase gasâliquid flows, using optical and capacitance tomography
2009
Abstract The paper presents a measurement method in testing horizontal two-phase gasâliquid flows. It also describes the test stand including two tomography measurement systems. The optical and capacitance tomography systems can be used for measurements at the same time. It is necessary to apply two tomography systems working at the same time because of complexity of phenomena occurring in two-phase flows, and a wide range of applicability of the presented method. The optical tomography system in which a tested object is illuminated from five projections. The measurement of luminous intensity is changed into a discrete signal (0 or 1) in the detectors including 64 optical sensors. Next, theâŠ
Measurement of CP asymmetries in the decays B0 â K*0 ÎŒ+ÎŒ- and B+ â K+ ÎŒ+ÎŒ-
2014
The direct CP asymmetries of the decays B 0 â K *0 ÎŒ + ÎŒ â and B + â K + ÎŒ + ÎŒ â are measured using pp collision data corresponding to an integrated luminosity of 3.0 fbâ1 collected with the LHCb detector. The respective control modes B 0 â J/ÏK *0 and B + â J/ÏK + are used to account for detection and production asymmetries. The measurements are made in several intervals of ÎŒ + ÎŒ â invariant mass squared, with the Ï(1020) and charmonium resonance regions excluded. Under the hypothesis of zero CP asymmetry in the control modes, the average values of the asymmetries are ACP(B0âKâ0ÎŒ+ÎŒâ)=â0.035±0.024±0.003,ACP(B+âK+ÎŒ+ÎŒâ)=0.012±0.017±0.001, where the first uncertainties are statistical and the âŠ
Implementation and performance of the third level muon trigger of the ATLAS experiment at LHC
2006
The trigger system of the ATLAS experiment at the LHC aims at a high selectivity in order to keep the full physics potential while reducing the 40 MHz initial event rate imposed by the LHC bunch crossing down to /spl sim/100 Hz, as required by the data acquisition system. Algorithms working in the final stage of the trigger environment (Event Filter) are implemented to run both in a "wrapped" mode (reconstructing tracks in the entire Muon Spectrometer) and in a "seeded" mode (according to a dedicated strategy that performs pattern recognition only in regions of the detector where trigger hypotheses have been produced at earlier stages). The working principles of the offline muon reconstructâŠ
Neutrino phenomenology and stable dark matter with A4
2011
We present a model based on the A4 non-abelian discrete symmetry leading to a predictive five-parameter neutrino mass matrix and providing a stable dark matter candidate. We found an interesting correlation among the atmospheric and the reactor angles which predicts theta_23 ~ pi/4 for very small reactor angle and deviation from maximal atmospheric mixing for large theta_13. Only normal neutrino mass spectrum is possible and the effective mass entering the neutrinoless double beta decay rate is constrained to be |m_ee| > 4 10^{-4} eV.
Admixture of quasi-Dirac and Majorana neutrinos with tri-bimaximal mixing
2011
7 pĂĄginas, 1 tabla.-- El Pdf es la versiĂłn pre-print: arXiv:1104.4961v2