25,654 research outputs found
Governance, rational choice and new public management (npm): a general view (and some critics)
This article aims to study the New Public Management (NPM), one of the main trends associated to neoliberalism. It studies governance to show its general, wider and abstract scope. It also focuses on the Rational Choice as an important theory about governance, a basis for NPM. And it observes the neoliberal foundations of NPM, showing critical aspects of its real practice. Methodology: hypothetical deductive method of research, with a qualitative and critical approach and bibliographic-documental research technique. As results of this research, we can conclude that: i) the ideological usage of NPM has been expressed in a culture of minimal state and
government - but in practice, such culture, when embossing implemented reforms, seldom reverted the role of the state, destroyed social safety nets, and placed the tax burden on the working majority rather than on the wealthy elite; ii) advocates for NPM have Western-shaped minds, generally making erroneous assumptions about institutions and cultures, which
may be present in Anglo-American countries, but not in other culturally different ones; iii) in practice, NPM reforms were imposed to low-income countries by donor institutions to adjust their states for good governance - but those reforms did not solve problems with inefficiency and corruption. This work is original and valuable because it shows that even
when public policies highlight the importance of less
state intervention, solid norms and institutions are
always necessary, and because it helps demystifying
discourses that simply put that less state/more market
politics can be valuable everywhere
Time (in)dependence in general relativity
We clarify the conditions for Birkhoff's theorem, that is, time-independence
in general relativity. We work primarily at the linearized level where guidance
from electrodynamics is particularly useful. As a bonus, we also derive the
equivalence principle. The basic time-independent solutions due to
Schwarzschild and Kerr provide concrete illustrations of the theorem. Only
familiarity with Maxwell's equations and tensor analysis is required.Comment: Revised version of originally titled "Kinder Kerr", to appear in
American Journal of Physic
Circular Symmetry in Topologically Massive Gravity
We re-derive, compactly, a TMG decoupling theorem: source-free TMG separates
into its Einstein and Cotton sectors for spaces with a hypersurface-orthogonal
Killing vector, here concretely for circular symmetry. We can then generalize
it to include matter, which is necessarily null.Comment: amplified published versio
No Bel-Robinson Tensor for Quadratic Curvature Theories
We attempt to generalize the familiar covariantly conserved Bel-Robinson
tensor B_{mnab} ~ R R of GR and its recent topologically massive third
derivative order counterpart B ~ RDR, to quadratic curvature actions. Two very
different models of current interest are examined: fourth order D=3 "new
massive", and second order D>4 Lanczos-Lovelock, gravity. On dimensional
grounds, the candidates here become B ~ DRDR+RRR. For the D=3 model, there
indeed exist conserved B ~ dRdR in the linearized limit. However, despite a
plethora of available cubic terms, B cannot be extended to the full theory. The
D>4 models are not even linearizable about flat space, since their field
equations are quadratic in curvature; they also have no viable B, a fact that
persists even if one includes cosmological or Einstein terms to allow
linearization about the resulting dS vacua. These results are an unexpected, if
hardly unique, example of linearization instability.Comment: published versio
The design of low cost structures for extensive ground arrays
The development of conceptual designs of solar array support structures and their foundations including considerations of the use of concrete, steel, aluminum, or timber are reported. Some cost trends were examined by varying selected parameters to determine optimum configurations. Detailed civil/structural design criteria were developed. Using these criteria, eight detailed designs for support structures and foundations were developed and cost estimates were made. As a result of the study wind was identified as the major loading experienced by these low height structures, whose arrays are likely to extend over large tracts of land. Proper wind load estimating is considered essential to developing realistic structural designs and achieving minimum cost support structures. Wind tunnel testing of a conceptual array field was undertaken and some of the resulting wind design criteria are presented. The SPS rectenna system designs may be less sensitive to wind load estimates, but consistent design criteria remain important
Some exact solutions of the Dirac equation
Exact analytic solutions are found to the Dirac equation for a combination of
Lorentz scalar and vector Coulombic potentials with additional non-Coulombic
parts. An appropriate linear combination of Lorentz scalar and vector
non-Coulombic potentials, with the scalar part dominating, can be chosen to
give exact analytic Dirac wave functions.Comment: 4 pages. No figures. Presented in Hadron 2000: International Workshop
on Hadron Physics, Caraguatatuba, SP, Brasil, April 200
Shortcuts to Spherically Symmetric Solutions: A Cautionary Note
Spherically symmetric solutions of generic gravitational models are
optimally, and legitimately, obtained by expressing the action in terms of the
two surviving metric components. This shortcut is not to be overdone, however:
a one-function ansatz invalidates it, as illustrated by the incorrect solutions
of [1].Comment: 2 pages. Amplified derivation, accepted for publication in Class
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