640 research outputs found

    Finite gravitational action for higher derivative and stringy gravities

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    We generalize the local surface counterterm prescription suggested in Einstein gravity for higher derivative (HD) and Weyl gravities. Explicitly, the surface counterterm is found for three- and five-dimensional HD gravities. As a result, the gravitational action for asymptotically AdS spaces is finite and gravitational energy-momentum tensor is well-defined. The holographic trace anomaly for d2 and d4 boundary (gauge) QFT dual to above HD gravity is calculated from gravitational energy-momentum tensor. The calculation of AdS black hole mass in HD gravity is presented within above prescrition. The comparison with the standard prescription (using reference spacetime) is done.Comment: LaTeX file, 21 page

    Duality of Quasilocal Gravitational Energy and Charges with Non-orthogonal Boundaries

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    We study the duality of quasilocal energy and charges with non-orthogonal boundaries in the (2+1)-dimensional low-energy string theory. Quasilocal quantities shown in the previous work and some new variables arisen from considering the non-orthogonal boundaries as well are presented, and the boost relations between those quantities are discussed. Moreover, we show that the dual properties of quasilocal variables such as quasilocal energy density, momentum densities, surface stress densities, dilaton pressure densities, and Neuve-Schwarz(NS) charge density, are still valid in the moving observer's frame.Comment: 19pages, 1figure, RevTe

    Proton Ground-state Correlations in the Even Calcium-isotopes

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    This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

    Density mismatch in thin diblock copolymer films

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    Thin films of diblock copolymer subject to gravitational field are simulated by means of a cell dynamical system model. The difference in density of the two sides of the molecule and the presence of the field causes the formation of lamellar patterns with orientation parallel to the confining walls even when they are neutral. The concentration profile of those films is analyzed in the weak segregation regime and a functional form for the profile is proposed.Comment: 9 pages and 8 figures. Needs EPSF macros. Submitted to PR

    Developing young people's sense of self and place through sport

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    Previous research has recognized positive health implications, both physical and mental, as an outcome of participation in leisure pursuits. They provide opportunities for self-expression and stress reduction, as well as an environment in which people can socialize. Leisure activities, specifically sport activities, can play a significant role in young people's identity development. This paper explores the leisure activities in which young people in Adelaide, Australia participate. It examines the role of leisure activities in terms of young people's identity and feelings towards their hometown. This study consisted of semi-structured focus groups conducted with 24 senior high school students, followed by a survey resulting in 226 useable responses. Respondents were aged between 16 and 18 years of age. From the range of activities identified and explored, the results revealed sports activities to have the greatest impact on young people's lives. The results demonstrated that frequency of participation has a significant effect on young people's involvement levels and how they identify with the activity

    New solutions in 3D gravity

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    We study gravitational theory in 1+2 spacetime dimensions which is determined by the Lagrangian constructed as a sum of the Einstein-Hilbert term plus the two (translational and rotational) gravitational Chern-Simons terms. When the corresponding coupling constants vanish, we are left with the purely Einstein theory of gravity. We obtain new exact solutions for the gravitational field equations with the nontrivial material sources. Special attention is paid to plane-fronted gravitational waves (in case of the Maxwell field source) and to the circularly symmetric as well as the anisotropic cosmological solutions which arise for the ideal fluid matter source.Comment: Revtex, 21 pages, no figure

    Hidden sl(2,R) Symmetry in 2D CFTs and the Wave Function of 3D Quantum Gravity

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    We show that all two-dimensional conformal field theories possess a hidden sl(2,R) affine symmetry. More precisely, we add appropriate ghost fields to an arbitrary CFT, and we use them to construct the currents of sl(2,R). We then define a BRST operator whose cohomology defines a physical subspace where the extended theory coincides with the original CFT. We use the sl(2,R) algebra to construct candidate wave functions for 3-d quantum gravity coupled to matter, and we discuss their viability.Comment: Minor misprints corrected.Eight references added. To appear in JHEP.34 pages, LaTe

    The Hyperfine Spin Splittings In Heavy Quarkonia

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    The hyperfine spin splittings in heavy quarkonia are studied using the recently developed renormalization group improved spin-spin potential which is independent of the scale parameter μ\mu. The calculated energy difference between the J/ψJ/\psi and the ηc\eta_c fits the experimental data well, while the predicted energy difference ΔMp\Delta M_p between the center of the gravity of 13P0,1,21^3P_{0,1,2} states and the 11P11^1P_1 state of charmonium has the correct sign but is somewhat larger than the experimental data. This is not surprising since there are several other contributions to ΔMp\Delta M_p, which we discuss, that are of comparable size (1\sim 1 MeV) that should be included, before precise agreement with the data can be expected. The mass differences of the ψηc\psi'-\eta_c', Υ(1S)ηb\Upsilon(1S)-\eta_b, Υ(2S)ηb\Upsilon(2S)-\eta_b', and BcBcB_c^*-B_c are also predicted.Comment: 17 page

    Interior Structure of a Charged Spinning Black Hole in (2+1)(2+1)-Dimensions

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    The phenomenon of mass inflation is shown to occur for a rotating black hole. We demonstrate this feature in (2+1)(2+1) dimensions by extending the charged spinning BTZ black hole to Vaidya form. We find that the mass function diverges in a manner quantitatively similar to its static counterparts in (3+1)(3+1), (2+1)(2+1) and (1+1)(1+1) dimensions.Comment: 5 pages, 2 figures (appended as postscript files), WATPHYS-TH94/0
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