7,025 research outputs found
Angular Momentum on the Lattice: The Case of Non-Zero Linear Momentum
The irreducible representations (IRs) of the double cover of the Euclidean
group with parity in three dimensions are subduced to the corresponding cubic
space group. The reduction of these representations gives the mapping of
continuum angular momentum states to the lattice in the case of non-zero linear
momentum. The continuous states correspond to lattice states with the same
momentum and continuum rotational quantum numbers decompose into those of the
IRs of the little group of the momentum vector on the lattice. The inverse
mapping indicates degeneracies that will appear between levels of different
lattice IRs in the continuum limit, recovering the continuum angular momentum
multiplets. An example of this inverse mapping is given for the case of the
``moving'' isotropic harmonic oscillator.Comment: v3) Little groups for lattice momenta corrected. Includes corrections
from erratum submitted to Phys. Rev. D and a more consistent labeling scheme.
v2) Minor changes to little groups. (9 pages
Transnational organizing: a case study of contract workers in the Colombian mining industry
This article examines recent organizing successes in the Carbones del Cerrejón coal mine, reversing the organizational crisis of the Colombian mining union, Sintracarbon. Using Wever's concept of ‘field-enlarging strategies’, we argue that these events were facilitated by the dissemination of organizing experiences between affiliates of a Global Union Federation, International Federation of Chemical, Energy, Mine and General Workers' Unions (ICEM), which recently merged to form IndustriALL. Additionally, we argue that this articulation between international and national unions, based on the principle of subsidiarity, was facilitated through sustained ICEM educational project activity, providing multiple entry points for Sintracarbon to operationalize its strategy and re-establish bargaining with multinational employers
Studies of satellite support to weather modification in the western US region
The applications of meteorological satellite data to both summer and winter weather modification programs are addressed. Appraisals of the capability of satellites to assess seedability, to provide real-time operational support, and to assist in the post-experiment analysis of a seeding experiment led to the incorporation of satellite observing systems as a major component in the Bureau of Reclamations weather modification activities. Satellite observations are an integral part of the South Park Area cumulus experiment (SPACE) which aims to formulate a quantitative hypothesis for enhancing precipitation from orographically induced summertime mesoscale convective systems (orogenic mesoscale systems). Progress is reported in using satellite observations to assist in classifying the important mesoscale systems, and in defining their frequency and coverage, and potential area of effect. Satellite studies of severe storms are also covered
A Data Exchange Standard for Optical (Visible/IR) Interferometry
This paper describes the OI Exchange Format, a standard for exchanging
calibrated data from optical (visible/infrared) stellar interferometers. The
standard is based on the Flexible Image Transport System (FITS), and supports
storage of the optical interferometric observables including squared visibility
and closure phase -- data products not included in radio interferometry
standards such as UV-FITS. The format has already gained the support of most
currently-operating optical interferometer projects, including COAST, NPOI,
IOTA, CHARA, VLTI, PTI, and the Keck Interferometer, and is endorsed by the IAU
Working Group on Optical Interferometry. Software is available for reading,
writing and merging OI Exchange Format files.Comment: 26 pages, 1 figur
Gender equalities: what lies ahead. Work, Employment and Society, 35 (4) . pp. 615-620. ISSN 0950-0170
It is hard to over-estimate the importance of the social sciences in informing us of deepening inequalities at work and how they are likely to play out as the economic crisis generated by the Covid-19 pandemic unfolds. Understanding the long-term impact of the pandemic requires us to think across the intersection of work and society. This is challenging work as part of taking an intersectional position means accepting that transmission thrives on inequality where occupation and occupational risk are often mapped onto class, race, ethnicity, sex and geography (Middleton et al., 2020). [...
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