5,700 research outputs found
Two-Dimensional Supersymmetric Quantum Mechanics: Two Fixed Centers of Force
The problem of building supersymmetry in the quantum mechanics of two
Coulombian centers of force is analyzed. It is shown that there are essentially
two ways of proceeding. The spectral problems of the SUSY (scalar) Hamiltonians
are quite similar and become tantamount to solving entangled families of Razavy
and Whittaker-Hill equations in the first approach. When the two centers have
the same strength, the Whittaker-Hill equations reduce to Mathieu equations. In
the second approach, the spectral problems are much more difficult to solve but
one can still find the zero-energy ground states.Comment: This is a contribution to the Proc. of the Seventh International
Conference ''Symmetry in Nonlinear Mathematical Physics'' (June 24-30, 2007,
Kyiv, Ukraine), published in SIGMA (Symmetry, Integrability and Geometry:
Methods and Applications) at http://www.emis.de/journals/SIGMA
Building research capacity for indigenous health : a case study of the National Health and Medical Research Council : the evolution and impact of policy and capacity building strategies for indigenous health research over a decade from 1996 to 2006
As Australia’s leading agency for funding health research (expending over $400 million in 2006), the National Health and Medical Research Council (NHMRC) has a major responsibility to improve the evidence base for health policy and practice. There is an urgent need for better evidence to guide policy and programs that improve the health of Indigenous peoples. In 2002, NHMRC endorsed a series of landmark policy changes to acknowledge its ongoing role and responsibilities in Indigenous health research—adopting a strategic Road Map for research, improving Indigenous representation across NHMRC Council and Principal Committees, and committing 5% of its annual budget to Indigenous health research. This thesis examines how these policies evolved, the extent to which they have been implemented, and their impact on agency expenditure in relation to People Support. Additionally, this thesis describes the impact of NHMRC policies in reshaping research practices among Indigenous populations
Spectroscopic and dynamical properties of comet C/2018 F4, likely a true average former member of the Oort cloud
The population of comets hosted by the Oort cloud is heterogeneous. Most
studies in this area focused on highly active objects, those with small
perihelion distances or examples of objects with peculiar physical properties
and/or unusual chemical compositions. This may have produced a biased sample of
Oort cloud comets in which the most common objects may be rare, particularly
those with perihelia well beyond the orbit of the Earth. Within this context,
the known Oort cloud comets may not be representative of the full sample. Here,
we study the spectral properties in the visible region and the cometary
activity of Comet C/2018 F4 (PANSTARRS). We also explore its orbital evolution
with the aim of understanding its origin within the context of known minor
bodies moving along nearly parabolic or hyperbolic paths. We present
observations obtained with the 10.4 m Gran Telescopio Canarias (GTC), derive
the spectral class and visible slope of C/2018 F4 and characterise its level of
cometary activity. Direct N-body simulations are carried out to explore its
orbital evolution. The absolute magnitude of C/2018 F4 is Hr=13.62+/-0.04.
Assuming a pV=0.04 its diameter is D<10.4 km. The object presents a conspicuous
coma, with a level of activity comparable to those of other comets observed at
similar heliocentric distances. Comet C/2018 F4 has a visible spectrum
consistent with that of an X-type asteroid, and has a spectral slope
S'=4.0+/-1.0 %/1000\AA and no evidence of hydration. The spectrum matches those
of well-studied primitive asteroids and comets. The analysis of its dynamical
evolution prior to discovery suggests that C/2018 F4 is not of extrasolar
origin. Although the present-day heliocentric orbit of C/2018 F4 is slightly
hyperbolic, its observational properties and past orbital evolution are
consistent with those of a dynamically old comet with an origin in the Oort
cloud.Comment: 6 pages, 5 figures. In pres
Implementation and Effects of LDC and MDC in Kentucky Districts
This brief summarizes early evidence on the success of two tools Kentucky districts have used to support their teachers' transition to these more demanding goals: Literacy Design Collaborative (LDC) and Math Design Collaborative (MDC). With support from the Bill and Melinda Gates Foundation, LDC and MDC tools have been designed and implemented to embody the key shifts in teaching and learning that the new standards demand. By implementing the tools, teachers then engage in new pedagogy and address relevant learning goals of the Kentucky Core Academic Standards
Factorization of supersymmetric Hamiltonians in curvilinear coordinates
Planar supersymmetric quantum mechanical systems with separable spectral
problem in curvilinear coordinates are analyzed in full generality. We
explicitly construct the supersymmetric extension of the Euler/Pauli
Hamiltonian describing the motion of a light particle in the field of two heavy
fixed Coulombian centers. We shall also show how the SUSY Kepler/Coulomb
problem arises in two different limits of this problem: either, the two centers
collapse in one center - a problem separable in polar coordinates -, or, one of
the two centers flies to infinity - to meet the Coulomb problem separable in
parabolic coordinates.Comment: 13 pages. Based on the talk presented by M.A. Gonzalez Leon at the
7th International Conference on Quantum Theory and Symmetries (QTS7), August
07-13, 2011, Prague, Czech Republi
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