1,568 research outputs found

    Torsion-Adding and Asymptotic Winding Number for Periodic Window Sequences

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    In parameter space of nonlinear dynamical systems, windows of periodic states are aligned following routes of period-adding configuring periodic window sequences. In state space of driven nonlinear oscillators, we determine the torsion associated with the periodic states and identify regions of uniform torsion in the window sequences. Moreover, we find that the measured of torsion differs by a constant between successive windows in periodic window sequences. We call this phenomenon as torsion-adding. Finally, combining the torsion and the period adding rules, we deduce a general rule to obtain the asymptotic winding number in the accumulation limit of such periodic window sequences

    Aspects of U-duality in BLG models with Lorentzian metric 3-algebras

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    In our previous paper, it was shown that BLG model based on a Lorentzian metric 3-algebra gives Dp-brane action whose worldvolume is compactified on torus T^d (d=p-2). Here the 3-algebra was a generalized one with d+1 pairs of Lorentzian metric generators and expressed in terms of a loop algebra with central extensions. In this paper, we derive the precise relation between the coupling constant of the super Yang-Mills, the moduli of T^d and some R-R flux with VEV's of ghost fields associated with Lorentzian metric generators. In particular, for d=1, we derive the Yang-Mills action with theta term and show that SL(2,Z) Montonen-Olive duality is realized as the rotation of two VEV's. Furthermore, some moduli parameters such as NS-NS 2-form flux are identified as the deformation parameters of the 3-algebras. By combining them, we recover most of the moduli parameters which are required by U-duality symmetry.Comment: 27 pages, v2: minor correction

    Fitting Brazilian livestock production to changes in natural and political environments.

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    Cattle production is the human activity with largest land use. Rises in demand for cattle products and steady or lower grasslands availability are projected, impelling high rates of productivity gain. However, greater pasture production seasonality in the main producing regions will challenge exclusive pasture-fed production in Brazil. Recovery of degraded pastureland, increasing feed supplementation and feedlots, and integration of livestock production with annual crops, forestry and ethanol agroindustry are promising strategies sustainable intensification under climate change. Digital transformation empowers society to influence public policies and products chains, rapidly changing production constraints and increasing demand for information from production systems. In this context, reducing vulnerability in the international market will demand national institutions and research teams to take part on international initiatives to produce new metrics, models, methods and analysis, which have the potential to affect the cattle industry. Lack of digital literacy of smallholder farmers in remote areas is also seen as an vulnerability, because of their reduced capacity to respond to this new connected environment

    Half-BPS quotients in M-theory: ADE with a twist

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    We classify Freund-Rubin backgrounds of eleven-dimensional supergravity of the form AdS_4 x X^7 which are at least half BPS; equivalently, smooth quotients of the round 7-sphere by finite subgroups of SO(8) which admit an (N>3)-dimensional subspace of Killing spinors. The classification is given in terms of pairs consisting of an ADE subgroup of SU(2) and an automorphism defining its embedding in SO(8). In particular we find novel half-BPS quotients associated with the subgroups of type D_n (for n>5), E_7 and E_8 and their outer automorphisms.Comment: 16 pages; V2: notational inconsistencies addressed, final version to be published in JHE

    Extração, secagem e beneficiamento de sementes de espécies florestais nativas.

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    Organizado por Patricia Póvoa de Mattos, Celso Garcia Auer, Rejane Stumpf Sberze, Katia Regina Pichelli e Paulo César Botosso
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