440 research outputs found

    Branching integrals and Casselman phenomenon

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    Let GG be a real semisimple Lie group, KK its maximal complex subgroup, and GCG_C its complexification. It is known that all the KK-finite matrix elements on GG admit holomorphic continuation to branching functions on GCG_C having singularities at the a prescribed divisor. We propose a geometric explanation of this phenomenon. The note also contsins a general survey of holomorphic continuations of infinite-dimensional representations.Comment: 13pp, an addendum is adde

    Quartet unconstrained formulation for massless higher spin fields

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    We construct simple unconstrained Lagrangian formulations for massless higher spin fields in flat space of arbitrary dimension and on anti de Sitter background. Starting from the triplet equations of Francia and Sagnotti, which describe a chain of spin modes, we introduce an auxiliary field and find appropriate gauge invariant constraints that single out the spin-s mode. The resulting quartet of fields, thus describing an irreducible representation of the Poincare group, is used to construct simple Lagrangian formulations, which are local, free from higher derivative terms and use equal number of auxiliary fields for an unconstrained description of any value of spin. Our method proves to be most efficient for an unconstrained description of massless higher spin fermions in anti de Sitter space. A relation of the minimal models with the universal BRST approach is discussed.Comment: V4: 27 pages; references and acknowledgement adde

    Two−photon Processes in Organometallic Molecules and Clusters: T−T Absorption of Group IV Metal Complexes

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    Triplet – triplet absorption of d0 metal complexes was for the first time revealed and studied by means of pulse photolysis and electron-exchange (Dexter) resonant energy transfer energy transfer. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3539

    Calibration curves and the chronology of key monuments at Sayan-Altai

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    Studies of the chronology of the elite barrows at Sayan-Altai are of a great importance for the determination of the origin and development of the cultures of the Scythian period. In this work dendrochronology and radiocarbon dating have been combined. Statistical calculations were used to obtain the best fit of the radiocarbon dates for the tree-ring series to the bidecadal calibration curve and thus to determine the zero point of the floatin g tree-ring chronology on the calendar time scale. The results obtained position the zero point of the floating tree-ring series in the calendar time period 380–420 BC with the confidence probability of 0.95. The goodness of fit can be improved by shifting the Arzhan tree-ring dates relative to the other tree-ring scale by 40 years. For all cases the age of the Arzhan barrow lies in the limit of 800 years BC. The results from chronological investigations of the constructions at the elite barrows of Sayan-Altai are summarised

    RF magnetron sputtered (BiDy)3(FeGa)5O12:Bi2O3 composite garnet-oxide materials possessing record magneto-optic quality in the visible spectral region

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    Bismuth-substituted iron garnets are considered to be the most promising magneto-optical materials because of their excellent optical transparency and very high magneto-optical figures of merit in the near-infrared spectral region. However, the practical application of garnets in the visible and short-wavelength infrared parts of spectrum is currently limited, due to their very high optical absorption (especially in sputtered films) in these spectral regions. In this paper, we identify the likely source of excess absorption observed in sputtered garnet films in comparison with epitaxial layers and demonstrate (Bi,Dy)(3)(Fe,Ga)(5)O(12): Bi(2)O(3) composites possessing record MO quality in the visible region

    LED Monitoring System for the BTeV Lead Tungstate Crystal Calorimeter Prototype

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    We report on the performance of a monitoring system for a prototype calorimeter for the BTeV experiment that uses Lead Tungstate crystals coupled with photomultiplier tubes. The tests were carried out at the 70 GeV accelerator complex at Protvino, Russia.Comment: 12 pages, 8 figures, LaTeX2e, revised versio

    Some problems in the study of the chronology of the ancient nomadic cultures in Eurasia (9th - 3rd centuries BC)

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    This research is focused on the chronological investigations of ancient nomads belonging to the Scythian cultures which occupied the steppe and forest-steppe zones of Eurasia during the 9th-3rd centuries BC. The 14C dates for the pre-scythian and early scythian time in both Europe and Asia are presented and compared to their chronological position based on archaeological evidence. The first 14C dates have been produced for the Scythian time monuments located in the Lower Volga River basin, Urals and Transurals regions. Their chronological positions are compared with the position of the monuments of Southern Siberia and Central Asia. It was shown that the nomadic cultures belonging to the Scythian culture began to exist over the wide territory of Eurasia from the 9th-8th centuries cal BC and there are some monuments which may be synchronous to the Arzhan royal barrow (the oldest monument known). A list of new 14C dates and a map of the monuments are presented

    BRST approach to Lagrangian construction for fermionic higher spin fields in AdS space

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    We develop a general gauge invariant Lagrangian construction for half-integer higher spin fields in the AdS space of any dimension. Starting with formulation in terms of auxiliary Fock space we derive the closed nonlinear symmetry algebras of higher spin fermionic fields in the AdS space and find the corresponding BRST operator. A universal procedure of constructing the gauge invariant Lagrangians describing the dynamics of fermionic fields of any spin is developed. No off-shell constraints for the fields and gauge parameters are imposed from the very beginning. It is shown that all the constraints determining the irreducible representation of the AdS group arise as a consequence of the equations of motion and gauge transformations. As an example of the general procedure, we derive the gauge invariant Lagrangians for massive fermionic fields of spin 1/2 and 3/2 containing the total set of auxiliary fields and gauge symmetries.Comment: Minor changes. Version accepted for publication in NP

    A chronology of the Scythian antiquities of Eurasia based on new archaeological and C-14 data

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    The paper is compares the chronology of the monuments of the Scythian epoch located in the east and west of the Eurasian steppe zone on the basis of both archaeological and radiocarbon data. The lists of C-14 dates for the monuments located in different parts of Eurasia are presented according to the periods of their existence. Generally, the C-14 dates are confirmed the archaeological point of view and allow us to compare the chronological position of the European and Asian Scythian monuments on the united C-14 time scale
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