14,610 research outputs found

    Relative Severi inequality for fibrations of maximal Albanese dimension over curves

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    Let f:XBf: X \to B be a relatively minimal fibration of maximal Albanese dimension from a variety XX of dimension n2n \ge 2 to a curve BB defined over an algebraically closed field of characteristic zero. We prove that KX/Bn2n!χfK_{X/B}^n \ge 2n! \chi_f, which was conjectured by Barja in [2]. Via the strategy outlined in [5], it also leads to a new proof of the Severi inequality for varieties of maximal Albanese dimension. Moreover, when the equality holds and χf>0\chi_f > 0, we prove that the general fiber FF of ff has to satisfy the Severi equality that KFn1=2(n1)!χ(F,ωF)K_F^{n-1} = 2(n-1)! \chi(F, \omega_F). We also prove some sharper results of the same type under extra assumptions.Comment: Comments are welcom

    Deforming black holes with even multipolar differential rotation boundary

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    Motivated by the novel asymptotically global AdS4_4 solutions with deforming horizon in [JHEP {\bf 1802}, 060 (2018)], we analyze the boundary metric with even multipolar differential rotation and numerically construct a family of deforming solutions with quadrupolar differential rotation boundary, including two classes of solutions: solitons and black holes. In contrast to solutions with dipolar differential rotation boundary, we find that even though the norm of Killing vector t\partial_t becomes spacelike for certain regions of polar angle θ\theta when ε>2\varepsilon>2, solitons and black holes with quadrupolar differential rotation still exist and do not develop hair due to superradiance. Moreover, at the same temperature, the horizonal deformation of quadrupolar rotation is smaller than that of dipolar rotation. Furthermore, we also study the entropy and quasinormal modes of the solutions, which have the analogous properties to that of dipolar rotation.Comment: 18 pages, 21 figure

    A abordagem do crescimento da firma a partir do processo acumulativo de capacitações: um estudo de caso da Shiseido

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    Relata a evolução empresarial da Shiseido, empresa japonesa de cosméticos e líder de mercado no Japão. A mesma começou como uma empresa familiar no século XIX e, atualmente, possui capital de 64,5 bilhões de ienes e atuação global, além de instalações de pesquisa e desenvolvimento (P&D) e fábricas fora do Japão. Atrelado a este relato buscou-se o suporte teórico de Marshall e Penrose quanto à abordagem de crescimento da firma em um processo acumulativo e dinâmico de capacitações. Ambos são de épocas e locais diferentes, onde predominaram distintas formas jurídicas de organização empresarial e, assim, formularam suas teorias de acordo com o meio de cada um, mas que são possíveis de complementação

    Modular Quantizations of Lie Algebras of Cartan Type K via Drinfeld Twists of Jordanian Type

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    We construct explicit Drinfel'd twists of Jordanian type for the generalized Cartan type K Lie algebras in characteristic 0 and obtain the corresponding quantizations, especially their integral forms. By making modular reductions including modulo p and modulo p-restrictedness reduction, and base changes, we derive certain modular quantizations of the restricted universal enveloping algebra u(K(2n+1;1))\mathbf u(\mathbf{K}(2n{+}1;\underline{1})) for the restricted simple Lie algebra of Cartan type K in characteristic p. They are new pointed Hopf algebras of noncommutative and noncocommutative and with dimension pp2n+1+1p^{p^{2n+1}+1} (if 2n+4≢0  (modp)2n+4\not\equiv0 \; (\mod p)) or pp2n+1p^{p^{2n+1}} (if 2n+40  (modp))2n+4\equiv0 \; (\mod p)) over a truncated p-polynomials ring, which also contain the well-known Radford algebras as Hopf subalgebras. Some open questions are proposed.Comment: arXiv admin note: substantial text overlap with arXiv:1202.5730, arXiv:0902.282

    Climate variation and incidence of Ross river virus in Cairns, Australia: a time-series analysis.

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    In this study we assessed the impact of climate variability on the Ross River virus (RRv) transmission and validated an epidemic-forecasting model in Cairns, Australia. Data on the RRv cases recorded between 1985 and 1996 were obtained from the Queensland Department of Health. Climate and population data were supplied by the Australian Bureau of Meteorology and the Australian Bureau of Statistics, respectively. The cross-correlation function (CCF) showed that maximum temperature in the current month and rainfall and relative humidity at a lag of 2 months were positively and significantly associated with the monthly incidence of RRv, whereas relative humidity at a lag of 5 months was inversely associated with the RRv transmission. We developed autoregressive integrated moving average (ARIMA) models on the data collected between 1985 to 1994, and then validated the models using the data collected between 1995 and 1996. The results show that the relative humidity at a lag of 5 months (p < 0.001) and the rainfall at a lag of 2 months (p < 0.05) appeared to play significant roles in the transmission of RRv disease in Cairns. Furthermore, the regressive forecast curves were consistent with the pattern of actual values
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