12,351 research outputs found
Analogues of Weyl's formula for reduced enveloping algebras
In this note we study simple modules for a reduced enveloping algebra
U_chi(g) in the critical case when chi element of g^* is ``nilpotent''. Some
dimension formulas computed by Jantzen suggest modified versions of Weyl's
dimension formula, based on certain reflecting hyperplanes for the affine Weyl
group which might be associated to Kazhdan--Lusztig cells.Comment: AMS-LaTeX, 10 pages, 2 figure
The Morphology of IRC +10420's Circumstellar Ejecta
Images of the circumstellar ejecta associated with the post-red supergiant
IRC +10420 show a complex ejecta with visual evidence for episodic mass loss.
In this paper we describe the transverse motions of numerous knots, arcs and
condensations in the inner ejecta measured from second epoch {\it HST/WFPC2}
images. When combined with the radial motions for several of the features, the
total space motion and direction of the outflows show that they were ejected at
different times, in different directions, and presumably from separate regions
on the surface of the star. These discrete structures in the ejecta are
kinematically distinct from the general expansion of the nebula and their
motions are dominated by their transverse velocities. They are apparently all
moving within a few degrees of the plane of the sky. We are thus viewing IRC
+10420 nearly pole-on and looking nearly directly down onto its equatorial
plane. We also discuss the role of surface activity and magnetic fields on IRC
+10420's recent mass loss history.Comment: 16 pages, 6 figure
Recommended from our members
Review of equality statistics
The Equality and Human Rights Commission (EHRC) commissioned this review as part of its remit to map the equalities landscape across England, Scotland and Wales. The report examines the extent to which data are available for the following equality strands: sex; ethnicity / race; disability; religion or belief; age; sexual orientation; and also for socio-economic status (social class). The extent to which statistics are available at different levels of geographic classification (UK, GB, England, Scotland and Wales and regional and local areas within this) is investigated. The report addresses the ten domains of equality identified in the equality measurement framework in the Equalities Review.1 These are: Longevity Physical security Health Education Standard of living Productive and valued activities Individual, family and social life Participation, influence and voice Identity, expression and self-respect Legal securit
Microbial Effects on Repository Performance
This report presents a critical review of the international literature on microbial effects
in and around a deep geological repository for higher activity wastes. It is aimed at
those who are familiar with the nuclear industry and radioactive waste disposal, but
who are not experts in microbiology; they may have a limited knowledge of how
microbiology may be integrated into and impact upon radioactive waste disposal
safety cases and associated performance assessments (PA)
Majorana meets Coxeter: Non-Abelian Majorana Fermions and Non-Abelian Statistics
We discuss statistics of vortices having zero-energy non-Abelian Majorana
fermions inside them. Considering the system of multiple non-Abelian vortices,
we derive a non-Abelian statistics that differs from the previously derived
non-Abelian statistics. The new non-Abelian statistics presented here is given
by a tensor product of two different groups, namely the non-Abelian statistics
obeyed by the Abelian Majorana fermions and the Coxeter group. The Coxeter
group is a symmetric group related to the symmetry of polytopes in a
high-dimensional space. As the simplest example, we consider the case in which
a vortex contains three Majorana fermions that are mixed with each other under
the SO(3) transformations. We concretely present the representation of the
Coxeter group in our case and its geometrical expressions in the
high-dimensional Hilbert space constructed from non-Abelian Majorana fermions.Comment: 6 pages, 4 figures, references added, published versio
Individualism-collectivism and interpersonal memory guidance of attention
Recently it has been shown that the allocation of attention by a participant in a visual search task can be affected by memory items that have to be maintained by a co-actor, when similar tasks are jointly engaged by dyads (He, Lever, & Humphreys, 2011). In the present study we examined the contribution of individualism-collectivism to this ‘interpersonal memory guidance’ effect. Actors performed visual search while a preview image was either held by the critical participant, held by a co-actor or was irrelevant to either participant. Attention during search was attracted to stimuli that matched the contents of the co-actor’s memory. This interpersonal effect correlated with the collectivism scores, and was enhanced by priming with a collectivistic scenario. The dimensions of individualism, however, did not contribute to performance. These data suggest that collectivism, but not individualism, modulates interpersonal influences on memory and attention in joint action
Mapping the potential within a nanoscale undoped GaAs region using a scanning electron microscope
Semiconductor dopant profiling using secondary electron imaging in a scanning
electron microscope (SEM) has been developed in recent years. In this paper, we
show that the mechanism behind it also allows mapping of the electric potential
of undoped regions. By using an unbiased GaAs/AlGaAs heterostructure, this
article demonstrates the direct observation of the electrostatic potential
variation inside a 90nm wide undoped GaAs channel surrounded by ionized
dopants. The secondary electron emission intensities are compared with
two-dimensional numerical solutions of the electric potential.Comment: 7 pages, 3 figure
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