2,638 research outputs found

    Canonical Quantization of SU(3) Skyrme Model in a General Representation

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    A complete canonical quantization of the SU(3) Skyrme model performed in the collective coordinate formalism in general irreducible representations. In the case of SU(3) the model differs qualitatively in different representations. The Wess-Zumino-Witten term vanishes in all self-adjoint representations in the collective coordinate method for separation of space and time variables. The canonical quantization generates representation dependent quantum mass corrections, which can stabilize the soliton solution. The standard symmetry breaking mass term, which in general leads to representation mixing, degenerates to the SU(2) form in all self-adjoint representations.Comment: 24 RevTex4 pages, no figure

    AMPTE/CCE‐SCATHA simultaneous observations of substorm‐associated magnetic fluctuations

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    This study examines substorm-associated magnetic field fluctuations observed by the AMPTE/CCE and SCATHA satellites in the near-Earth tail. Three tail reconfiguration events are selected, one event on August 28, 1986, and two consecutive events on August 30, 1986. The fractal analysis was applied to magnetic field measurements of each satellite. The result indicates that (1) the amplitude of the fluctuation of the north-south magnetic component is larger, though not overwhelmingly, than the amplitudes of the other two components and (2) the magnetic fluctuations do have a characteristic timescale, which is several times the proton gyroperiod. In the examined events the satellite separation was less than 10 times the proton gyroradius. Nevertheless, the comparison between the AMPTE/CCE and SCATHA observations indicates that (3) there was a noticeable time delay between the onsets of the magnetic fluctuations at the two satellite positions, which is too long to ascribe to the propagation of a fast magnetosonic wave, and (4) the coherence of the magnetic fluctuations was low in the August 28, 1986, event and the fluctuations had different characteristic timescales in the first event of August 30, 1986, whereas some similarities can be found for the second event of August 30, 1986. Result 1 indicates that perturbation electric currents associated with the magnetic fluctuations tend to flow parallel to the tail current sheet and are presumably related to the reduction of the tail current intensity. Results 2 and 3 suggest that the excitation of the magnetic fluctuations and therefore the trigger of the tail current disruption is a kinetic process in which ions play an important role. It is inferred from results 3 and 4 that the characteristic spatial scale of the associated instability is of the order of the proton gyroradius or even shorter, and therefore the tail current disruption is described as a system of chaotic filamentary electric currents. However, result 4 suggests that the nature of the tail current disruption can vary from event to event

    Experimental ordinary language philosophy: a cross-linguistic study of defeasible default inferences

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    This paper provides new tools for philosophical argument analysis and fresh empirical foundations for ‘critical’ ordinary language philosophy. Language comprehension routinely involves stereotypical inferences with contextual defeaters. J.L. Austin’s Sense and Sensibilia first mooted the idea that contextually inappropriate stereotypical inferences from verbal case-descriptions drive some philosophical paradoxes; these engender philosophical problems that can be resolved by exposing the underlying fallacies. We build on psycholinguistic research on salience effects to explain when and why even perfectly competent speakers cannot help making stereotypical inferences which are contextually inappropriate. We analyse a classical paradox about perception (‘argument from illusion’), suggest it relies on contextually inappropriate stereotypical inferences from appearance-verbs, and show that the conditions we identified as leading to contextually inappropriate stereotypical inferences are met in formulations of the paradox. Three experiments use a forced-choice plausibility-ranking task to document the predicted inappropriate inferences, in English, German, and Japanese. The cross-linguistic study allows us to assess the wider relevance of the proposed analysis. Our findings open up new perspectives for ‘evidential’ experimental philosophy

    Photometric Observations of Star Formation Activity in Early Type Spirals

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    We observationally study the current star formation activities of early type spiral galaxies. We construct a complete sample of 15 early type spirals having far-infrared (FIR) to optical B band luminosity ratios, L(FIR)/L(B), larger than the average of the type, and make their CCD imaging of the R and H-alpha bands. The equivalent widths of H-alpha emission increase with increasing L(FIR)/L(B), indicating that L(FIR)/L(B) can be an indicator of star formation for such early type spirals with star formation activities higher than the average. For all of the observed early type spirals, the extended HII regions exist at the central regions with some asymmetric features. H-alpha emission is more concentrated to the galactic center than the R band light, and the degree of the concentration increases with the star formation activity. We also analyze the relation between the star formation activities and the existence of companion galaxies in the sample galaxies and other bright early type spirals. No correlation is found and this suggests that the interaction is not responsible for all of the star formation activities of early type spirals.Comment: LaTex, 23 pages (2 tables included), plus 9 Postscript figures & 1 table. To be published in AJ (November issue

    Hall-effect and resistivity measurements in CdTe and ZnTe at high pressure: Electronic structure of impurities in the zincblende phase and the semi-metallic or metallic character of the high-pressure phases

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    We carried out high-pressure resistivity and Hall-effect measurements in single crystals of CdTe and ZnTe up to 12 GPa. Slight changes of transport parameters in the zincblende phase of CdTe are consitent with the shallow character of donor impurities. Drastic changes in all the transport parameters of CdTe were found around 4 GPa, i.e. close to the onset of the cinnabar to rock-salt transition. In particular, the carrier concentration increases by more than five orders of magnitude. Additionally, an abrupt decrease of the resistivity was detected around 10 GPa. These results are discussed in comparison with optical, thermoelectric, and x-ray diffraction experiments. The metallic character of the Cmcm phase of CdTe is confirmed and a semi-metallic character is determined for the rock-salt phase. In zincblende ZnTe, the increase of the hole concentration by more than two orders of magnitude is proposed to be due to a deep-to-shallow transformation of the acceptor levels. Between 9 and 11 GPa, transport parameters are consistent with the semiconducting character of cinnabar ZnTe. A two orders of magnitude decrease of the resistivity and a carrier-type inversion occurs at 11 GPa, in agreement with the onset of the transition to the Cmcm phase of ZnTe. A metallic character for this phase is deduced.Comment: 20 pages, 4 figure

    Discovery of coesite and stishovite in HED meteorite

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    第3回極域科学シンポジウム/第35回南極隕石シンポジウム 11月29日(木) 国立国語研究所 2階講
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