294 research outputs found
Membrane in M5-branes Background
In this paper, we investigate the properties of a membrane in the M5-brane
background. Through solving the classical equations of motion of the membrane,
we can understand the classical dynamics of the membrane in this background.Comment: 15 pages, typos correcte
Macroscopic and Microscopic Entropy of Near-Extremal Spinning Black Holes
A seven parameter family of five-dimensional black hole solutions depending
on mass, two angular momenta, three charges and the asymptotic value of a
scalar field is constructed. The entropy is computed as a function of these
parameters both from the Bekenstein-Hawking formula and from the degeneracies
of the corresponding D-brane states in string theory. The expressions agree at
and to leading order away from extremality.Comment: 7 pages, harvma
Young star clusters in M31
In our study of M31's globular cluster system with MMT/Hectospec, we have
obtained high-quality spectra of 85 clusters with ages less than 1 Gyr. With
the exception of Hubble V, the young cluster in NGC 205, we find that these
young clusters have kinematics and spatial distribution consistent with
membership in M31's young disk. Preliminary estimates of the cluster masses and
structural parameters, using spectroscopically derived ages and HST imaging,
confirms earlier suggestions that M31 has clusters similar to the LMC's young
populous clusters.Comment: 4 pages, 1 figure, contributed talk at "Galaxies in the Local Volume"
conference in Sydney, July 200
Spin Transfer Measurements for (p,n) Reactions at Intermediate Energy
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
The Initial Mass Function in disc galaxies and in galaxy clusters: the chemo-photometric picture
The observed brightness of the Tully-Fisher relation suggests a low stellar
M/L ratio and a "bottom-light" IMF in disc galaxies, but the corresponding
efficiency of chemical enrichment tends to exceed the observational estimates.
Either suitable tuning of the IMF slope and mass limits or metal outflows from
disc galaxies must then be invoked.
A standard Solar Neighbourhood IMF cannot explain the high metallicity of the
hot intra-cluster medium: a different IMF must be at work in clusters of
galaxies. Alternatively, if the IMF is universal and chemical enrichment is
everywhere as efficient as observed in clusters, substantial loss of metals
must occur from the Solar Neighbourhood and from disc galaxies in general; a
"non-standard" scenario challenging our understanding of disc galaxy formation.Comment: 6 pages, 4 figures; in Proceedings of IMF@50: the Initial Mass
Function 50 years later; Corbelli, Palla and Zinnecker (eds.
Measurements of Gamow-Teller Strength Distributions in Masses 13 and 15
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
Folded Three-Spin String Solutions in AdS_5 x S^5
We construct a spinning closed string solution in AdS_5 x S^5 which is folded
in the radial direction and has two equal spins in AdS_5 and a spin in S^5. The
energy expression of the three-spin solution specified by the folding and
winding numbers for the small S^5 spin shows a logarithmic behavior and a
one-third power behavior of the large total AdS_5 spin, in the long string and
in the short string located near the boundary of AdS_5 respectively. It
exhibits the non-regular expansion in the 't Hooft coupling constant, while it
takes the regular one when the S^5 spin becomes large.Comment: 14 pages, LaTeX, no figures, a reference adde
On the Classical String Solutions and String/Field Theory Duality
We classify almost all classical string configurations, considered in the
framework of the semi-classical limit of the string/gauge theory duality. Then,
we describe a procedure for obtaining the conserved quantities and the exact
classical string solutions in general string theory backgrounds, when the
string embedding coordinates depend non-linearly on the worldsheet time
parameter.Comment: LaTeX, 15 pages, no figures; V2: some typos corrected; V3: no
corrections, to appear in JHE
All Vacuum Near-Horizon Geometries in -dimensions with Commuting Rotational Symmetries
We explicitly construct all stationary, non-static, extremal near horizon
geometries in dimensions that satisfy the vacuum Einstein equations, and
that have commuting rotational symmetries. Our work generalizes
[arXiv:0806.2051] by Kunduri and Lucietti, where such a classification had been
given in . But our method is different from theirs and relies on a
matrix formulation of the Einstein equations. Unlike their method, this matrix
formulation works for any dimension. The metrics that we find come in three
families, with horizon topology , or ,
or quotients thereof. Our metrics depend on two discrete parameters specifying
the topology type, as well as continuous parameters. Not all of
our metrics in seem to arise as the near horizon limits of known
black hole solutions.Comment: 22 pages, Latex, no figures, title changed, references added,
discussion of the parameters specifying solutions corrected, amended to match
published versio
Future research priorities for lichen sclerosus – results of a James Lind Alliance Priority Setting Partnership
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