640 research outputs found
Finite gravitational action for higher derivative and stringy gravities
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
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
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
Density mismatch in thin diblock copolymer films
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
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
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
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
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 . The calculated energy difference
between the and the fits the experimental data well, while
the predicted energy difference between the center of the gravity
of states and the 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 , which we discuss,
that are of comparable size ( MeV) that should be included, before
precise agreement with the data can be expected. The mass differences of the
, , , and
are also predicted.Comment: 17 page
Interior Structure of a Charged Spinning Black Hole in -Dimensions
The phenomenon of mass inflation is shown to occur for a rotating black hole.
We demonstrate this feature in 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 ,
and dimensions.Comment: 5 pages, 2 figures (appended as postscript files), WATPHYS-TH94/0
- …