3,884 research outputs found

    Charges in nonlinear higher-spin theory

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    Nonlinear higher-spin equations in four dimensions admit a closed two-form that defines a gauge-invariant global charge as an integral over a two-dimensional cycle. In this paper we argue that this charge gives rise to partitions depending on various lower- and higher-spin chemical potentials identified with modules of topological fields in the theory. The vacuum contribution to the partition is calculated to the first nontrivial order for a solution to higher-spin equations that generalizes AdS4 Kerr black hole of General Relativity. The resulting partition is non-zero being in parametric agreement with the ADM-like behavior of a rotating source. The linear response of chemical potentials to the partition function is also extracted. The explicit unfolded form of 4d GR black holes is given. An explicit formula relating asymptotic higher-spin charges expressed in terms of the generalized higher-spin Weyl tensor with those expressed in terms of Fronsdal fields is obtained.Comment: 23 pages; V3: typos corrected; references and acknowledgement added; example of the topological contribution to spin-4 charge added; new Section 3.1 added establishing relation of our construction for asymptotic charges with the canonical one. Version published in JHE

    Lorentz covariant form of extended higher-spin equations

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    The extension of nonlinear higher-spin equations in d=4 proposed in [arXiv:1504.07289] for the construction of invariant functional is shown to respect local Lorentz symmetry. The equations are rewritten in a manifestly Lorentz covariant form resulting from some Stueckelberg-like field transformation. We also show that the two field-independent central terms entering higher-spin equations which are not entirely fixed by the consistency alone get fixed unambiguously by the requirement of Lorentz symmetry. One of the important advantages of the proposed approach demonstrated in the paper is the remarkable simplification of the perturbative analysis.Comment: V2: 20 pages, typos corrected, references added. Version published in JHE

    Beam halo dynamics and control with hollow electron beams

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    Experimental measurements of beam halo diffusion dynamics with collimator scans are reviewed. The concept of halo control with a hollow electron beam collimator, its demonstration at the Tevatron, and its possible applications at the LHC are discussed.Comment: 5 pages, 4 figures, in Proceedings of the 52nd ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB2012), Beijing, China, 17-21 September 201

    Experimental and Theoretical Investigation into the Effect of the Electron Velocity Distribution on Chaotic Oscillations in an Electron Beam under Virtual Cathode Formation Conditions

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    The effect of the electron transverse and longitudinal velocity spread at the entrance to the interaction space on wide-band chaotic oscillations in intense multiple-velocity beams is studied theoretically and numerically under the conditions of formation of a virtual cathode. It is found that an increase in the electron velocity spread causes chaotization of virtual cathode oscillations. An insight into physical processes taking place in a virtual cathode multiple velocity beam is gained by numerical simulation. The chaotization of the oscillations is shown to be associated with additional electron structures, which were separated out by constructing charged particle distribution functions.Comment: 9 pages, 8 figure

    ХАРАКТЕРИСТИКИ САМОПОДОБИЯ СЕЙСМИЧНОСТИ И РАЗЛОМНОЙ СЕТИ СИХОТЭ‐АЛИНЬСКОГО ОРОГЕННОГО ПОЯСА И ПРИЛЕГАЮЩИХ ТЕРРИТОРИЙ

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    We performed a comprehensive analysis of the characteristics of self‐similarity of seismicity and the fault network within the Sikhote Alin orogenic belt and the adjacent areas. It has been established that the main features of seismicity are controlled by the crustal earthquakes. Differentiation of the study area according to the density of earthquake epicenters and the fractal dimension of the epicentral field of earthquakes (De) shows that the most active crustal areas are linked to the Kharpi‐Kur‐Priamurye zone, the northern Bureya massif and the Mongol‐Okhotsk folded system. The analysis of the earthquake recurrence plot slope values reveals that the highest b‐values correlate with the areas of the highest seismic activity of the northern part of the Bureya massif and, to a less extent, of the Mongol‐Okhotsk folded system. The increased fractal dimension values for the fault network (Df) correlate with the folded systems (Sikhote Alin and Mongol‐Okhotsk), while the decreased values conform to the depressions and troughs (Middle Amur, Uda and Torom). A comparison of the fractal analysis results for the fault network with the recent stress‐strain data gives evidence of their general confineness to the contemporary areas of intense compression. The correspondence between the field of the parameter b‐value for the upper crustal earthquakes and the fractal dimension value for the fault network (Df) suggests a general consistency between the self‐similar earthquake magnitude (energy) distribution and the fractal distribution of the fault sizes. The analysis results demonstrate that the selfsimilarity parameters provide an important quantitative characteristic in seismotectonics and can be used for the neotectonic and geodynamic analyses.Проведен комплексный анализ характеристик самоподобия сейсмичности и сети разломов в пределах Сихотэ‐Алиньского орогенного пояса и прилегающих территорий. Установлено, что основные осо‐ бенности сейсмичности определяются коровыми землетрясениями. Дифференциация исследуемой территории по плотности эпицентров и величине фрактальной размерности поля эпицентров (De) показывает, что наиболее активные участки земной коры связаны с Харпийско‐Курско‐Приамурской зоной, с северной частью Буреинского массива и Монголо‐Охотской складчатой системой. Анализ значений наклона графика повторяемости землетрясений (b) показывает, что наибольшие его величины соответствует районам наибольшей сейсмической активности: северной части Буреинского массива и, в меньшей степени, – Монголо‐Охотской системе. Повышенные значения фрактальной размерности разломной сети (Df) соответствуют складчатым системам (Сихотэ‐Алиньской и Монголо‐Охотской), а пониженные – впадинам и прогибам (Среднеамурская, Удский и Торомский). Сопоставление результатов фрактального анализа сети разломов с данными по современному напряженно‐деформированному состоянию показывает их общую приуроченность к областям интенсивного современного сжатия. Соответствие поля параметра b для верхнекоровых землетрясений и поля размерности сети разломов Df указывает на общую согласованность самоподобного распределения магнитуды (энергии) землетрясений и фрактального распределения размеров разрывных нарушений. Полученные результаты показывают, что параметры самоподобия являются важной количественной характеристикой в сейсмотектонике и могут использоваться при неотектоническом и геодинамическом анализе

    Investigation of the Chaotic Dynamics of an Electron Beam with a Virtual Cathode in an External Magnetic Field

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    The effect of the strength of the focusing magnetic field on chaotic dynamic processes occurring inan electron beam with a virtual cathode, as well as on the processes whereby the structures form in the beamand interact with each other, is studied by means of two-dimensional numerical simulations based on solving a self-consistent set of Vlasov-Maxwell equations. It is shown that, as the focusing magnetic field is decreased,the dynamics of an electron beam with a virtual cathode becomes more complicated due to the formation andinteraction of spatio-temporal longitudinal and transverse structures in the interaction region of a vircator. The optimum efficiency of the interaction of an electron beam with the electromagnetic field of the vircator isachieved at a comparatively weak external magnetic field and is determined by the fundamentally two-dimensional nature of the motion of the beam electrons near the virtual cathode.Comment: 12 pages, 8 figure

    BTZ Black Hole as Solution of 3d Higher Spin Gauge Theory

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    BTZ black hole is interpreted as exact solution of 3d higher spin gauge theory. Solutions for free massless fields in BTZ black hole background are constructed with the help of the star-product algebra formalism underlying the formulation of 3d higher spin theory. It is shown that a part of higher spin symmetries remains unbroken for special values of the BTZ parameters.Comment: 31 pages, LaTeX; references correcte

    Complex of C₆₀ fullerene with doxorubicin as a promising agent in antitumor therapy

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    The main aim of this work was to evaluate the effect of doxorubicin in complex with C₆₀ fullerene (C₆₀ + Dox) on the growth and metastasis of Lewis lung carcinoma in mice and to perform a primary screening of the potential mechanisms of C₆₀ + Dox complex actio

    Complex of C₆₀ fullerene with doxorubicin as a promising agent in antitumor therapy

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    The main aim of this work was to evaluate the effect of doxorubicin in complex with C₆₀ fullerene (C₆₀ + Dox) on the growth and metastasis of Lewis lung carcinoma in mice and to perform a primary screening of the potential mechanisms of C₆₀ + Dox complex actio
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