5,969 research outputs found
Reply to "Comment on 'Gravitating Magnetic Monopole in the Global Monopole Spacetime' "
In this Reply I present some arguments in favor of the stability of the
topological defect composed by global and magnetic monopoles.Comment: 1 page, no figures. Revised version improves the theoretical analysis
about electrostatic self-interaction in the global monopole spacetim
A Multiwavelength Study on the Fate of Ionizing Radiation in Local Starbursts
The fate of ionizing radiation is vital for understanding cosmic ionization,
energy budgets in the interstellar and intergalactic medium, and star formation
rate indicators. The low observed escape fractions of ionizing radiation have
not been adequately explained, and there is evidence that some starbursts have
high escape fractions. We examine the spectral energy distributions of a sample
of local star-forming galaxies, containing thirteen local starburst galaxies
and ten of their ordinary star-forming counterparts, to determine if there
exist significant differences in the fate of ionizing radiation in these
galaxies. We find that the galaxy-to-galaxy variations in the SEDs is much
larger than any systematic differences between starbursts and non-starbursts.
For example, we find no significant differences in the total absorption of
ionizing radiation by dust, traced by the 24um, 70um, and 160um MIPS bands of
the Spitzer Space Telescope, although the dust in starburst galaxies appears to
be hotter than that of non-starburst galaxies. We also observe no excess
ultraviolet flux in the GALEX bands that could indicate a high escape fraction
of ionizing photons in starburst galaxies. The small H-alpha fractions of the
diffuse, warm ionized medium in starburst galaxies are apparently due to
temporarily boosted H-alpha luminosity within the star-forming regions
themselves, with an independent, constant WIM luminosity. This independence of
the WIM and starburst luminosities contrasts with WIM behavior in non-starburst
galaxies and underscores our poor understanding of radiation transfer in both
ordinary and starburst galaxies.Comment: 10 pages, 8 figures, accepted to ApJ 10/11/1
AdS_4/CFT_3 Construction from Collective Fields
We pursue the construction of higher-spin theory in AdS_4 from CFT_3 of the
O(N) vector model in terms of canonical collective fields. In null plane
quantization an exact map is established between the two spaces. The
coordinates of the AdS_4 space-time are generated from the collective
coordinates of the bi-local field. This, in the light cone gauge, provides an
exact one to one reconstruction of bulk AdS_4 space-time and higher-spin
fields.Comment: 17 pages, no figures; v2: references added; v3: minor change
Determinação de metil-xantinas em alimentos por cromatografia lÃquida de alta eficiência.
bitstream/item/75983/1/ct55-2002.pd
Vacuum Polarization for a Massless Spin-1/2 Field in the Global Monopole Spacetime at Nonzero Temperature
In this paper we present the effects produced by the temperature in the
renormalized vacuum expectation value of the zero-zero component of the
energy-momentum tensor associated with massless left-handed spinor field in the
pointlike global monopole spacetime. In order to develop this calculation we
had to obtain the Euclidean thermal Green function in this background. Because
the expression obtained for the thermal energy density cannot be expressed in a
closed form, its explicit dependence on the temperature is not completely
evident. So, in order to obtain concrete information about its thermal
behavior, we develop a numerical analysis of our result in the high-temperature
limit for specific values of the parameter which codify the presence
of the monopole.Comment: 22 pages, LaTex format, 5 figure
Matrix Model Maps and Reconstruction of AdS SUGRA Interactions
We consider the question of reconstructing (cubic) SUGRA interactions in
AdS/CFT. The method we introduce is based on the matrix model maps (MMP) which
were previously successfully employed at the linearized level. The strategy is
to start with the map for 1/2 BPS configurations which is exactly known (to all
orders) in the hamiltonian framework. We then use the extension of the matrix
model map with the corresponding Ward identities to completely specify the
interaction. A central point in this construction is the non-vanishing of
off-shell interactions (even for highest-weight states).Comment: 28 page
Perfil sócio-econômico e tecnológico das propriedades viticolas dos municÃpios de Bento Gonçalves e Flores da Cunha - RS.
bitstream/item/60666/1/CNPUV-DOC.-3-87.pd
Transformações na estrutura produtiva dos viticultores da Serra Gaúcha: 1985/1991.
bitstream/item/58187/1/CNPUV-DOC.-7-92.pd
The self-energy of a charged particle in the presence of a topological defect distribution
In this work we study a charged particle in the presence of both a continuous
distribution of disclinations and a continuous distribution of edge
dislocations in the framework of the geometrical theory of defects. We obtain
the self-energy for a single charge both in the internal and external regions
of either distribution. For both distributions the result outside the defect
distribution is the self-energy that a single charge experiments in the
presence of a single defect.Comment: 12 pages, Revtex4, two figures,to appear in Int. Joun. Mod. Phys.
Correlators of Giant Gravitons from dual ABJ(M) Theory
We generalize the operators of ABJM theory, given by Schur polynomials, in
ABJ theory by computing the two point functions in the free field and at finite
limits. These polynomials are then identified with the states of
the dual gravity theory. Further, we compute correlators among giant gravitons
as well as between giant gravitons and ordinary gravitons through the
corresponding correlators of ABJ(M) theory. Finally, we consider a particular
non-trivial background produced by an operator with an -charge of
and find, in presence of this background, due to the contribution of
the non-planar corrections, the large expansion is replaced by
and respectively.Comment: Latex, 32+1 pages, 2 figures, journal versio
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