3,833 research outputs found

    Emergence of gravity from interacting simplices

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    We consider a statistical model of interacting 4-simplices fluctuating in an N-dimensional target space. We argue that a gravitational theory may arise as a low energy effective theory in a strongly interacting phase where the simplices form clusters with an emergent space and time with the Euclidean signature. In the large N limit, two possible phases are discussed, that is, `gravitational Coulomb phase' and `gravitational Higgs phase'.Comment: 18 pages, 6 figures, one-column format; major revisions in version 5 : reviews on emergent gauge theories added; microscopic simplex model for emergent gravity added; erroneous statements on diffeomorphism invariance remove

    Stability of the U(1) spin liquid with spinon Fermi surface in 2+1 dimensions

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    We study the stability of the 2+1 dimensional U(1) spin liquid state against proliferation of instantons in the presence of spinon Fermi surface. By mapping the spinon Fermi surface into an infinite set of 1+1 dimensional chiral fermions, it is argued that an instanton has an infinite scaling dimension for any nonzero number of spinon flavors. Therefore, the spin liquid phase is stable against instantons and the non-compact U(1) gauge theory is a good low energy description.Comment: 14 pages, 7 figures, v3) minor corrections, to appear in PR

    Scrutinising the exceptionalism of young rural NEETs: A bibliometric review

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    The situation of rural NEETs aged 15 to 24 remains understudied. However, transitions from adolescence to emerging adulthood are very demanding for those in the countryside. Our paper discusses this gap by characterising the scholarship focusing on rural NEETs. We undertook a bibliometric review based on 325 entries on Web of Science (WoS) using the Bibliometrix analysis package. Our approach included descriptive bibliometric analysis, co-citation networks assessment, and thematic analysis. Our findings show that the investigation efforts depicting younger rural NEET are recent and marginal in the larger context of international NEETs scholarship. The field is dominated by economy- and sociology-led networks. Concerns regarding health and employment issues are central in international publishing trends, showing a dominant youth-at-risk approach to this group. Still, themes associated with adolescent NEETs and relevant programs’ assessment are gaining traction. Our findings show a need for funding research initiatives to reduce the invisibility of young rural NEETs.info:eu-repo/semantics/acceptedVersio

    Higgs Mediated EDMs in the Next-to-MSSM: An Application to Electroweak Baryogenesis

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    We perform a study on the predictions of electric-dipole moments (EDMs) of neutron, Mercury (Hg), Thallium (Tl), deuteron, and Radium (Ra) in the framework of next-to-minimal supersymmetric standard model (NMSSM) with CP-violating parameters in the superpotential and soft-supersymmetry-breaking sector. We confine to the case in which only the physical tree-level CP phase (ϕλϕκ)(\phi'_\lambda - \phi'_\kappa), associated with the couplings of the singlet terms in the superpotential and with the vacuum-expectation-values (VEVs), takes on a nonzero value. We found that the one-loop contributions from neutralinos are mostly small while the two-loop Higgs-mediated contributions of the Barr-Zee (BZ) type diagrams dominate. We emphasize a scenario motivated by electroweak baryogenesis.Comment: 36 pages, 9 figures, to appear in PR

    Discovery of Coupling between Periodic and Aperiodic Variability and X-ray Quasi-periodic Oscillations from Her X-1

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    We report the discovery of coupling between periodic and aperiodic variability and ~12-mHz X-ray quasi-periodic oscillations (QPOs) from the X-ray binary pulsar Her X-1 using data from the Rossi X-Ray Timing Explorer. We found two different couplings, one during the pre-eclipse dips and the other during the normal state of the source, using a method which directly compares the low-frequency power-density spectra (PDS) with those of the sidebands around the coherent pulse frequency. The pre-eclipse dip lightcurves show significant time variation of photon counts, and this variation appears in the PDS as both strong mHz powers and well-developed sidebands around the coherent pulse frequency. The linear correlation coefficients between the mHz PDS and the sideband PDS obtained from two pre-eclipse dip data segments are 0.880 +- 0.003 and 0.982 +- 0.001, respectively. This very strong coupling demonstrates that the amplitudes of the coherent pulsations are almost exactly modulated by the aperiodic variabilities, suggesting that both the periodic and aperiodic variabilities are related to time variation of obscuration of X-rays from the central pulsar by an accretion disk during pre-eclipse dips. We also found weak coupling during the normal state of the source, together with ~12-mHz QPOs. The normal state coupling seems to reconcile with the prediction that the aperiodic variabilities from X-ray binary pulsars are due to time-varying accretion flows onto the pulsar's magnetic poles. If the ~12-mHz QPOs are due to global-normal disk oscillations caused by the gravitational interactions between the central pulsar and the accretion disk, the inferred inner-disk radius is roughly comparable to the magnetospheric radius, ~1 10^8 cm.Comment: 13 pages (including 5 figures), submitted to ApJL (revised after referee's report

    Electron Heat Flow Due to Magnetic Field Fluctuations

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    Radial heat transport induced by magnetic field line fluctuations is obtained from the integral parallel heat flow closure for arbitrary collisionality. The parallel heat flow and its radial component are computed for a single harmonic sinusoidal field line perturbation. In the collisional and collisionless limits, averaging the heat flow over an unperturbed surface yields Rechester-Rosenbluth like formulae with quantitative factors. The single harmonic result is generalized to multiple harmonics given a spectrum of small magnetic perturbations. In the collisionless limit, the heat and particle transport relations are also derived. © 2016 IOP Publishing Ltd

    [Fe II] and H2 filaments in the Supernova Remnant G11.2-0.3: Supernova Ejecta and Presupernova Circumstellar Wind

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    We present the results of near-infrared imaging and spectroscopic observations of the young, core-collapse supernova remnant (SNR) G11.2-0.3. In the [Fe II] 1.644 um image, we first discover long, clumpy [Fe II] filaments within the radio shell of the SNR, together with some faint, knotty features in the interior of the remnant. We have detected several [Fe II] lines and HI Br-G line toward the peak position of the bright southeastern [Fe II] filament. The derived extinction is large (Av=13 mag) and it is the brightest [Fe II] filament detected toward SNRs to date. By analyzing two [Fe II] 1.644 um images obtained in 2.2 yrs apart, we detect a proper motion corresponding to an expansion rate of 0.''035 (0.''013) /yr [or 830 (310) km/s]. We also discover two small H2 filaments. One is bright and along the SE boundary of the radio shell, while the other is faint and just outside of its NE boundary. We have detected H2 (2-1) S(3) line toward the former filament and derive an excitation temperature of 2,100 K. We suggest that the H2 filaments are dense clumps in a presupernova circumstellar wind swept up by the SNR shock while the [Fe II] filaments are probably composed of both shocked wind material and shocked supernova (SN) ejecta. The distribution of [Fe II] filaments may indicate that the SN explosion in G11.2-0.3 was asymmetric as in Cassiopeia A. Our results support the suggestion that G11.2-0.3 is a remnant of a SN IIL/b interacting with a dense red supergiant wind.Comment: 30 pages with 10 figures, To appear in the Astrophysical Journa

    Perancangan Peta Jalan Pengembangunan Industri Hasil Pertanian Pada Wilayah Kabupaten Dengan Metode VRISA Dan Rantai Nilai

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    .Industry development is an alternative in social welfare improvement of a region. This research was conducted to develop a road map of industry development in Kabupaten Bengkayang, West Kalimantan. VRISA (Value, Rare, In-imitabillity, Substitutability and Appropriability) framework used to determine appropriate industrial products to be developed. Based on value chain method, the development strategy was constructed into main value chain and supporting value chain strategy. Output of analysis showed that corn-based product was preferred by VRISA framework, so it needs to be developed as appropriate industry for Kabupaten Bengkayang. There are three stages of industrial development in the corn-based industry, namely initial phase (basic foundation establishment), main phase (implementation), and final stage (harvesting). Time frame for all stages takes five years
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