2,850 research outputs found
Complementarity of dark matter detectors in light of the neutrino background
Direct detection dark matter experiments looking for WIMP-nucleus elastic
scattering will soon be sensitive to an irreducible background from neutrinos
which will drastically affect their discovery potential. Here we explore how
the neutrino background will affect future ton-scale experiments considering
both spin-dependent and spin-independent interactions. We show that combining
data from experiments using different targets can improve the dark matter
discovery potential due to target complementarity. We find that in the context
of spin-dependent interactions, combining results from several targets can
greatly enhance the subtraction of the neutrino background for WIMP masses
below 10 GeV/c and therefore probe dark matter models to lower
cross-sections. In the context of target complementarity, we also explore how
one can tune the relative exposures of different target materials to optimize
the WIMP discovery potential.Comment: 13 pages, 12 figures, 3 table
The holonomy of IIB supercovariant connection
We show that the holonomy of the supercovariant connection of IIB
supergravity is contained in SL(32, \bR). We also find that the holonomy
reduces to a subgroup of SL(32-N)\st (\oplus^N \bR^{32-N}) for IIB
supergravity backgrounds with Killing spinors. We give the necessary and
sufficient conditions for a IIB background to admit Killing spinors. A IIB
supersymmetric probe configuration can involve up to 31 linearly independent
planar branes and preserves one supersymmetry.Comment: 8 pages, latex. v2: Minor correction
A One-Parameter Family of Hamiltonian Structures for the KP Hierarchy and a Continuous Deformation of the Nonlinear \W_{\rm KP} Algebra
The KP hierarchy is hamiltonian relative to a one-parameter family of Poisson
structures obtained from a generalized Adler map in the space of formal
pseudodifferential symbols with noninteger powers. The resulting \W-algebra
is a one-parameter deformation of \W_{\rm KP} admitting a central extension
for generic values of the parameter, reducing naturally to \W_n for special
values of the parameter, and contracting to the centrally extended
\W_{1+\infty}, \W_\infty and further truncations. In the classical limit,
all algebras in the one-parameter family are equivalent and isomorphic to
\w_{\rm KP}. The reduction induced by setting the spin-one field to zero
yields a one-parameter deformation of \widehat{\W}_\infty which contracts to
a new nonlinear algebra of the \W_\infty-type.Comment: 31 pages, compressed uuencoded .dvi file, BONN-HE-92/20, US-FT-7/92,
KUL-TF-92/20. [version just replaced was truncated by some mailer
Rocket Testing and Integrated System Health Management
Integrated System Health Management (ISHM) describes a set of system capabilities that in aggregate perform: determination of condition for each system element, detection of anomalies, diagnosis of causes for anomalies, and prognostics for future anomalies and system behavior. The ISHM should also provide operators with situational awareness of the system by integrating contextual and timely data, information, and knowledge (DIaK) as needed. ISHM capabilities can be implemented using a variety of technologies and tools. This chapter provides an overview of ISHM contributing technologies and describes in further detail a novel implementation architecture along with associated taxonomy, ontology, and standards. The operational ISHM testbed is based on a subsystem of a rocket engine test stand. Such test stands contain many elements that are common to manufacturing systems, and thereby serve to illustrate the potential benefits and methodologies of the ISHM approach for intelligent manufacturing
Knots in Chern-Simons Field Theory
Knots in the Chern-Simons field theory with Lie super gauge group
are studied, and the polynomial invariant with skein relations are obtained under the fundamental
representation of .Comment: 15 pages, 5 figure
Dynamics of intersecting brane systems -- Classification and their applications --
We present dynamical intersecting brane solutions in higher-dimensional
gravitational theory coupled to dilaton and several forms. Assuming the forms
of metric, form fields, and dilaton field, we give a complete classification of
dynamical intersecting brane solutions with/without M-waves and Kaluza-Klein
monopoles in eleven-dimensional supergravity. We apply these solutions to
cosmology and black holes. It is shown that these give FRW cosmological
solutions and in some cases Lorentz invariance is broken in our world. If we
regard the bulk space as our universe, we may interpret them as black holes in
the expanding universe. We also discuss lower-dimensional effective theories
and point out naive effective theories may give us some solutions which are
inconsistent with the higher-dimensional Einstein equations.Comment: 44 pages; v2: minor corrections, references adde
Resultado a corto plazo de la artroplastia no cementada modelo Mittelmeier
Los autores han revisado 56 Artroplastias de Cadera no cementada
empleando prótesis de Cerámica. Describen su técnica quirúrgica exponiendo
los resultados obtenidos.
Todos estos pacientes han sido operados en el Hospital Insular de las
Palmas de Gran Canaria, en el periodo comprendido entre 1984 y 1988.56 Cementedless Total Hip Prothesis of Ceramic are colected.
The authors describe their surgical procedure showing the results
obtained
AGN heating, thermal conduction and Sunyaev-Zeldovich effect in galaxy groups and clusters
(abridged) We investigate in detail the role of active galactic nuclei on the
physical state of the gas in galaxy groups and clusters, and the implications
for anisotropy in the CMB from Sunyaev-Zeldovich effect. We include the effect
of thermal conduction, and find that the resulting profiles of temperature and
entropy are consistent with observations. Unlike previously proposed models,
our model predicts that isentropic cores are not an inevitable consequence of
preheating. The model also reproduces the observational trend for the density
profiles to flatten in lower mass systems. We deduce the energy E_agn required
to explain the entropy observations as a function of mass of groups and
clusters M_cl and show that E_agn is proportional to M_cl^alpha with alpha~1.5.
We demonstrate that the entropy measurements, in conjunction with our model,
can be translated into constraints on the cluster--black hole mass relation.
The inferred relation is nonlinear and has the form M_bh\propto M_cl^alpha.
This scaling is an analog and extension of a similar relation between the black
hole mass and the galactic halo mass that holds on smaller scales. We show that
the central decrement of the CMB temperature is reduced due to the enhanced
entropy of the ICM, and that the decrement predicted from the plausible range
of energy input from the AGN is consistent with available data of SZ decrement.
We show that AGN heating, combined with the observational constraints on
entropy, leads to suppression of higher multipole moments in the angular power
spectrum and we find that this effect is stronger than previously thought.Comment: accepted for publication in The Astrophysical Journa
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