2,186 research outputs found

    Urban occupations in a Siberian city (Tobolsk, 1897)

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    The article was submitted on 27.06.2016.Рассматривается профессиональная структура города Тобольска конца ХIX в. Сибирь была самым масштабным регионом Российской империи со слабо развитой сетью городов, большинство из которых выполняли роль опорных центров для административного управления огромной территорией. В наиболее освоенных и развитых в хозяйственном отношении западных и южных губерниях Сибири города становились не только административными, но и культурными, и экономическими их центрами. Вопрос представляется актуальным для понимания готовности сибирских губерний к тем общественным трансформациям, которые начались спустя два десятилетия после рассматриваемого периода. Особенностью исследования является использование персональных данных Первой всеобщей переписи населения Российской империи 1897 г. На уровне персоналий оно позволяет существенно расширить исследовательский диапазон, ранее ограниченный опубликованными агрегированными материалами. С их помощью дана характеристика занятости городского населения крупных сибирских городов, показана специфика занятости «военных», «аграрных» городов, а также губернских центров Западной и Восточной Сибири. Обработка данных переписи 1897 г. на индивидуальном уровне производилась с помощью базы данных «Население Тобольска в 1897 г.», включающей сведения о 92,5 % горожан, имевших самостоятельные занятия. Персональные данные позволили провести реконструкцию возрастной и гендерной структуры экономически активного населения губернского центра, выявить особенности занятости представителей разных сословных групп, специфику дополнительных занятий городского населения, определить влияние семьи на выбор сферы деятельности человека. Все сведения о занятиях населения городов Сибири, в том числе Тобольска, были закодированы с помощью Historical International Standard Classification of Occupations.The article studies the late 19th-century occupational structure of Tobolsk in the context of other major Siberian cities. Many urban centres were strongholds for governing this huge territory, and Tobolsk was a typical provincial capital in this regard. In the most economically developed Western and Southern Siberian provinces, cities were not only administrative hubs, but also cultural and economic centres. The authors look at how urban populations were distributed among different occupational groups and social classes, and what role gender and family relations played in terms of employment. This is important, as it may help understand whether Russia’s huge eastern provinces were ready for the transformations which started just two decades after the period whence the main source material of the article originates. The research is based on the first general census of the Russian Empire in 1897. The archives have not preserved primary census manuscripts as a unified collection: so far, only scattered manuscripts have emerged. Clearly, the use of the individual-level nominative census data found for Tobolsk considerably broadens the scope of the research, which was previously limited to aggregate data. The aggregate data provide an opportunity to characterise employment in Siberian cities more generally, demonstrating the occupational specificity of the ‘military’ and ‘agrarian’ cities as well as the provincial centres of Western and Eastern Siberia. The authors more closely analyse the nominative 1897 census data using the database ‘Tobolsk Population in 1897’, which contains information about 92.5 % of employed citizens. The individual-level data made it possible to reconstruct the age and gender structure of the economically active population of the provincial centre, to study the occupations of different estate groups, to look into specific features of secondary occupations, and to see the family’s influence on the choice of occupation. All the employment data on the Siberian urban population were coded according to the HISCO standard

    A Method to Determine Vcb|V_{cb}| at the Weak Scale in Top Decays at the LHC

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    Until now, the Cabibbo Kobayashi Maskawa matrix element, Vcb|V_{cb}|, has always been measured in BB decays, i.e.~at an energy scale qbmb2q_b\sim \frac{m_b}{2}, far below the weak scale. We consider here the possibility of measuring it close to the weak scale, at qWmWq_W\sim m_W, in top decays at the Large Hadron Collider (LHC). Our proposed method would use data from the LHC experiments in hadronic top decays tbWbbct\rightarrow bW\rightarrow b\overline{b} c, tagged by the semileptonic decay of the associated top. We estimate the uncertainty of such a measurement, as a function of present and potential future experimental jet flavour-tagging performances, and conclude that first measurements using the data collected during 2016 - 2018 could yield a fractional error on \Vcb\ of order 7\% per experiment. We also give projected performances at higher luminosities, which could yield sensitivity to any Standard Model running of \Vcb\ below the weak scale, if present.Comment: 15 pages, 1 figures. Changes for V3: removed earlier Fig. 1, associated text and citations, added one new citatio

    Noncommutative magnetic moment of charged particles

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    It has been argued, that in noncommutative field theories sizes of physical objects cannot be taken smaller than an elementary length related to noncommutativity parameters. By gauge-covariantly extending field equations of noncommutative U(1)_*-theory to the presence of external sources, we find electric and magnetic fields produces by an extended charge. We find that such a charge, apart from being an ordinary electric monopole, is also a magnetic dipole. By writing off the existing experimental clearance in the value of the lepton magnetic moments for the present effect, we get the bound on noncommutativity at the level of 10^4 TeV.Comment: 9 pages, revtex; v2: replaced to match the published versio

    Phase transitions in spinor quantum gravity on a lattice

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    We construct a well-defined lattice-regularized quantum theory formulated in terms of fundamental fermion and gauge fields, the same type of degrees of freedom as in the Standard Model. The theory is explicitly invariant under local Lorentz transformations and, in the continuum limit, under diffeomorphisms. It is suitable for describing large nonperturbative and fast-varying fluctuations of metrics. Although the quantum curved space turns out to be on the average flat and smooth owing to the non-compressibility of the fundamental fermions, the low-energy Einstein limit is not automatic: one needs to ensure that composite metrics fluctuations propagate to long distances as compared to the lattice spacing. One way to guarantee this is to stay at a phase transition. We develop a lattice mean field method and find that the theory typically has several phases in the space of the dimensionless coupling constants, separated by the second order phase transition surface. For example, there is a phase with a spontaneous breaking of chiral symmetry. The effective low-energy Lagrangian for the ensuing Goldstone field is explicitly diffeomorphism-invariant. We expect that the Einstein gravitation is achieved at the phase transition. A bonus is that the cosmological constant is probably automatically zero.Comment: 37 pages, 12 figures Discussion of dimensions and of the Berezinsky--Kosterlitz--Thouless phase adde

    Direct observation of mode-coupling instability in two-dimensional plasma crystals

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    Dedicated experiments on melting of 2D plasma crystals were carried out. The melting was always accompanied by spontaneous growth of the particle kinetic energy, suggesting a universal plasma-driven mechanism underlying the process. By measuring three principal dust-lattice (DL) wave modes simultaneously, it is unambiguously demonstrated that the melting occurs due to the resonance coupling between two of the DL modes. The variation of the wave modes with the experimental conditions, including the emergence of the resonant (hybrid) branch, reveals exceptionally good agreement with the theory of mode-coupling instability.Comment: 4 pages, submitted to Physical Review Letter

    Cavity solitons in vertical-cavity surface-emitting lasers

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    We investigate a control of the motion of localized structures of light by means of delay feedback in the transverse section of a broad area nonlinear optical system. The delayed feedback is found to induce a spontaneous motion of a solitary localized structure that is stationary and stable in the absence of feedback. We focus our analysis on an experimentally relevant system namely the Vertical-Cavity Surface-Emitting Laser (VCSEL). In the absence of the delay feedback we present experimental evidence of stationary localized structures in a 80 μ\mum aperture VCSEL. The spontaneous formation of localized structures takes place above the lasing threshold and under optical injection. Then, we consider the effect of the time-delayed optical feedback and investigate analytically the role of the phase of the feedback and the carrier lifetime on the self-mobility properties of the localized structures. We show that these two parameters affect strongly the space time dynamics of two-dimensional localized structures. We derive an analytical formula for the threshold associated with drift instability of localized structures and a normal form equation describing the slow time evolution of the speed of the moving structure.Comment: 7 pages, 5 figure
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