480 research outputs found

    The vacuum state of quantum gravity contains large virtual masses

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    In the functional integral approach to quantum gravity, the quantum configurations are usually treated to order hbar through a stationary phase approximation around the saddle point of the action where spacetime is flat. We show that from this point a "level line" in functional space departs, which comprises a family of static non-flat metrics with zero scalar curvature, depending on a continuous mass parameter. Furthermore, each of these metrics can be perturbed by an arbitrary function in such a way to still satisfy the condition Int(gR)d4x=0. We thus find a set of zero-modes of the gravitational action which has non-vanishing measure in the functional space. These metrics will contribute to the functional integral as vacuum fluctuations, on the same footing as those near the saddle point.Comment: 13 pages, 4 figures; to appear in Class. Q. Gravit

    Import Substitution and Opportunities for Industrial Cooperation Chains in the Yenisei Regions of Siberia

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    Геополитический кризис 2022 г. поставил перед национальной экономикой задачу по обеспечению технологического суверенитета и замещению импорта важных для развития страны товаров и услуг. Поскольку размещение оперативных и статистических данных о товарной структуре внешнеэкономической деятельности ограничено до 01.07.2023 г., в настоящее время возможна лишь косвенная оценка. Обладающие развитым промышленным производством регионы Енисейской Сибири, так же как и Россия в целом, критически зависят от импорта двух типов товаров – продуктов неорганической химии и машиностроения, которые занимают в совокупном импорте товаров макрорегиона 70–90 %. Зависимость отечественной экономики от иностранных поставок по этим группам товаров наполовину приходится на страны ЕС и Северную Америку, наполовину – на Китай. В сложившихся условиях возникает необходимость развертывания собственного производства требуемой продукции на территории макрорегиона или встраивания в существующие производственные цепочки посредством кооперации различных предприятийThe geopolitical crisis of 2022 has challenged the national economy to ensure technological sovereignty and substitute imports of goods and services important for the country’s development. Since the posting of operational and statistical data on the commodity structure of foreign economic activity is limited to 01.07.2023, only an indirect assessment is possible at present. The regions of Yenisei Siberia with developed industrial production, as well as Russia as a whole, critically depend on the import of two types of goods – products of inorganic chemistry and mechanical engineering, which occupy 70–90 % in the total import of goods of the macro-region. The dependence of the domestic economy on foreign supplies for these product groups is half on the EU and North America, and half on China. In these circumstances, there is a need for the macro-region to establish its own production of necessary products or to integrate them into existing production chains through the cooperation of various enterprise

    `Iconoclastic', Categorical Quantum Gravity

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    This is a two-part, `2-in-1' paper. In Part I, the introductory talk at `Glafka--2004: Iconoclastic Approaches to Quantum Gravity' international theoretical physics conference is presented in paper form (without references). In Part II, the more technical talk, originally titled ``Abstract Differential Geometric Excursion to Classical and Quantum Gravity'', is presented in paper form (with citations). The two parts are closely entwined, as Part I makes general motivating remarks for Part II.Comment: 34 pages, in paper form 2 talks given at ``Glafka--2004: Iconoclastic Approaches to Quantum Gravity'' international theoretical physics conference, Athens, Greece (summer 2004

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum