16,097 research outputs found
The Continuous Spectrum in Discrete Series Branching Laws
If is a reductive Lie group of Harish-Chandra class, is a symmetric
subgroup, and is a discrete series representation of , the authors
give a condition on the pair which guarantees that the direct integral
decomposition of contains each irreducible representation of with
finite multiplicity. In addition, if is a reductive Lie group of
Harish-Chandra class, and is a closed, reductive subgroup of
Harish-Chandra class, the authors show that the multiplicity function in the
direct integral decomposition of is constant along `continuous
parameters'. In obtaining these results, the authors develop a new technique
for studying multiplicities in the restriction via convolution with
Harish-Chandra characters. This technique has the advantage of being useful for
studying the continuous spectrum as well as the discrete spectrum.Comment: International Journal of Mathematics, Volume 24, Number 7, 201
Wave Front Sets of Reductive Lie Group Representations
If is a Lie group, is a closed subgroup, and is a
unitary representation of , then the authors give a sufficient condition on
to be in the wave front set of
. In the special case where is the trivial
representation, this result was conjectured by Howe. If is a real,
reductive algebraic group and is a unitary representation of that is
weakly contained in the regular representation, then the authors give a
geometric description of in terms of the direct
integral decomposition of into irreducibles. Special cases of this result
were previously obtained by Kashiwara-Vergne, Howe, and Rossmann. The authors
give applications to harmonic analysis problems and branching problems.Comment: Accepted to Duke Mathematical Journa
Moral disengagement of hotel guest negative WOM : moral identity centrality, moral awareness, and anger
Adopting a moral identity perspective, this research examines the moral judgment of hotel guests’ vindictive negative word of mouth (WOM) toward hotel service failure. This research finds that people with higher moral identity centrality are less prone to moral disengagement of vindictive negative WOM, especially when their moral awareness of the behavior is higher. However, even these individuals may engage in moral disengagement of vindictive negative WOM, if they have higher anger toward the service failure, and when their moral awareness is lower. These findings highlight the significant roles of moral identity centrality, moral awareness, and moral emotion for people’s moral judgment. Practically, this research suggests hotels may manage customer vindictive negative WOM by raising moral awareness and appeasing anger
Dorsoventral patterning of the Xenopus eye involves differential temporal changes in the response of optic stalk and retinal progenitors to Hh signalling
Background: Hedgehog (Hh) signals are instrumental to the dorsoventral patterning of the vertebrate eye, promoting optic stalk and ventral retinal fates and repressing dorsal retinal identity. There has been limited analysis, however, of the critical window during which Hh molecules control eye polarity and of the temporal changes in the responsiveness of eye cells to these signals.
Results: In this study, we used pharmacological and molecular tools to perform stage-specific manipulations of Hh signalling in the developing Xenopus eye. In gain-of-function experiments, most of the eye was sensitive to ventralization when the Hh pathway was activated starting from gastrula/neurula stages. During optic vesicle stages, the dorsal eye became resistant to Hh-dependent ventralization, but this pathway could partially upregulate optic stalk markers within the retina. In loss-of-function assays, inhibition of Hh signalling starting from neurula stages caused expansion of the dorsal retina at the expense of the ventral retina and the optic stalk, while the effects of Hh inhibition during optic vesicle stages were limited to the reduction of optic stalk size.
Conclusions: Our results suggest the existence of two competence windows during which the Hh pathway differentially controls patterning of the eye region. In the first window, between the neural plate and the optic vesicle stages, Hh signalling exerts a global influence on eye dorsoventral polarity, contributing to the specification of optic stalk, ventral retina and dorsal retinal domains. In the second window, between optic vesicle and optic cup stages, this pathway plays a more limited role in the maintenance of the optic stalk domain. We speculate that this temporal regulation is important to coordinate dorsoventral patterning with morphogenesis and differentiation processes during eye development
CP Test in J/Psi -> gamma phi phi Decay
We propose to test CP symmetry in the decay \jp\to \gamma \phi\phi, for
which large data sample exists at BESII, and a data sample of
's will be collected with BESIII and CLEO-C program. We suggest some CP
asymmetries in this decay mode for CP test. Assuming that CP violation is
introduced by the electric- and chromo-dipole moment of charm quark, these CP
asymmetries can be predicted by using valence quark models. Our work shows a
possible way to get information about the electric- and chromo-dipole moment of
charm quark, which is little known. Our results show that with the current data
sample of , electric- and chromo-dipole moment can be probed at order
of . In the near future with a data sample, these
moments can be probed at order of .Comment: Misprints corrected. To appear in Phys. Lett.
OBCS: The Ontology of Biological and Clinical Statistics
Statistics play a critical role in biological and clinical research. To promote logically consistent representation and classification of statistical entities, we have developed the Ontology of Biological and Clinical Statistics (OBCS). OBCS extends the Ontology of Biomedical Investigations (OBI), an OBO Foundry ontology supported by some 20 communities. Currently, OBCS contains 686 terms, including 381 classes imported from OBI and 147 classes specific to OBCS. The goal of this paper is to present OBCS for community critique and to describe a number of use cases designed to illustrate its potential applications. The OBCS project and source code are available at http://obcs.googlecode.com
Thin film superfluid optomechanics
Excitations in superfluid helium represent attractive mechanical degrees of
freedom for cavity optomechanics schemes. Here we numerically and analytically
investigate the properties of optomechanical resonators formed by thin films of
superfluid He covering micrometer-scale whispering gallery mode cavities.
We predict that through proper optimization of the interaction between film and
optical field, large optomechanical coupling rates kHz
and single photon cooperativities are achievable. Our analytical model
reveals the unconventional behaviour of these thin films, such as thicker and
heavier films exhibiting smaller effective mass and larger zero point motion.
The optomechanical system outlined here provides access to unusual regimes such
as and opens the prospect of laser cooling a liquid into its
quantum ground state.Comment: 18 pages, 6 figure
Microphotonic Forces From Superfluid Flow
In cavity optomechanics, radiation pressure and photothermal forces are
widely utilized to cool and control micromechanical motion, with applications
ranging from precision sensing and quantum information to fundamental science.
Here, we realize an alternative approach to optical forcing based on superfluid
flow and evaporation in response to optical heating. We demonstrate optical
forcing of the motion of a cryogenic microtoroidal resonator at a level of 1.46
nN, roughly one order of magnitude larger than the radiation pressure force. We
use this force to feedback cool the motion of a microtoroid mechanical mode to
137 mK. The photoconvective forces demonstrated here provide a new tool for
high bandwidth control of mechanical motion in cryogenic conditions, and have
the potential to allow efficient transfer of electromagnetic energy to motional
kinetic energy.Comment: 5 pages, 6 figure
Modelling of vorticity, sound and their interaction in two-dimensional superfluids
Vorticity in two-dimensional superfluids is subject to intense research
efforts due to its role in quantum turbulence, dissipation and the BKT phase
transition. Interaction of sound and vortices is of broad importance in
Bose-Einstein condensates and superfluid helium [1-4]. However, both the
modelling of the vortex flow field and of its interaction with sound are
complicated hydrodynamic problems, with analytic solutions only available in
special cases. In this work, we develop methods to compute both the vortex and
sound flow fields in an arbitrary two-dimensional domain. Further, we analyse
the dispersive interaction of vortices with sound modes in a two-dimensional
superfluid and develop a model that quantifies this interaction for any vortex
distribution on any two-dimensional bounded domain, possibly non-simply
connected, exploiting analogies with fluid dynamics of an ideal gas and
electrostatics. As an example application we use this technique to propose an
experiment that should be able to unambiguously detect single circulation
quanta in a helium thin film.Comment: 23 pages, 8 figure
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