2,671 research outputs found

    Capital flows to South Asian and ASEAN countries : trends, determinants, and policy implications

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    The authors compare the experiences of selected Asian countries in attracting different forms of external financing and examine how that financing has contributed to growth. They carry out the analysis for two subgroups - South Asian and ASEAN countries - with distinctly different dominant forms of capital flows. After reviewing recent trends in financial flows to individual countries, they perform a statistical analysis of the effects of foreign capital flows on the macroeconomic performance of developing countries in the region. They find that foreign direct investment has been a more significant positive factor than other types of resource flows in shaping the economic growth of ASEAN countries. Substantial increases in ODA flows are unlikely, and so is the resumption of significant bank lending, so policy makers in South Asia should pursue policies and nondistortionary incentive systems conducive to the infusion of foreign direct investment flows. The main findings are consistent with the Bank's emphasis on an increasingly important role for the private sector - and direct investment flows - in development. A focus on foreign direct investment is appropriate, given current constraints on external financing, particularly through traditional bank credits.Economic Theory&Research,Banks&Banking Reform,International Terrorism&Counterterrorism,Environmental Economics&Policies,Financial Intermediation

    Black hole solutions in 2+1 dimensions

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    We give circularly symmetric solutions for null fluid collapse in 2+1-dimensional Einstein gravity with a cosmological constant. The fluid pressure PP and energy density ρ\rho are related by P=kρP=k\rho (k≀1)(k\le 1). The long time limit of the solutions are black holes whose horizon structures depend on the value of kk. The k=1k=1 solution is the Banados-Teitelboim-Zanelli black hole metric in the long time static limit, while the k<1k<1 solutions give other, `hairy' black hole metrics in this limit.Comment: 8 pages, RevTeX (to appear in Phys. Rev. D) References to Mann and Ross, and Mann, Chan and Chan adde

    Quantum black holes from null expansion operators

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    Using a recently developed quantization of spherically symmetric gravity coupled to a scalar field, we give a construction of null expansion operators that allow a definition of general, fully dynamical quantum black holes. These operators capture the intuitive idea that classical black holes are defined by the presence of trapped surfaces, that is surfaces from which light cannot escape outward. They thus provide a mechanism for classifying quantum states of the system into those that describe quantum black holes and those that do not. We find that quantum horizons fluctuate, confirming long-held heuristic expectations. We also give explicit examples of quantum black hole states. The work sets a framework for addressing the puzzles of black hole physics in a fully quantized dynamical setting.Comment: 5 pages, version to appear in CQ

    Kontrol Sosial Harian Palopo Pos Dalam Mewujudkan Good Governance Di Luwu Social Control of Palopo Pos Daily Newspaper in Realizing Good Governance at Luwu

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    This research is aimed to analyse the trends of good governance rubric presented at Daily Palopo Post, and role of this media in realizing good governance ini Luwu. The discussion of the research based on the question do Daily Palopo Post was able to become media control for local governance and also become mediator among the society, government party and also the private sectors. This research was performed by analyzing the trends of good governance rubric presented at Daily Palopo Post, and also the role of Palopo Post in realizing good governance during three months by using content analyse a descriptive method quantitative. The election of information technique was taken an entirely of population as sampel along May–June 2009. The research result shown that 1). The content of News daily Palopo Post on good governance was much more published the authority abuse based on governmental information source. That theme principle good governance also were published the accountability principle as implementation of government public responsibility; and 2) Daily Palopo Post has a role ini dissemination of information and performed social control function especially as media which stimulated public awareness in order to enabled their role in controlling governance affairs toward better good governance managemen

    Dynamic range of nanotube- and nanowire-based electromechanical systems

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    Nanomechanical resonators with high aspect ratio, such as nanotubes and nanowires are of interest due to their expected high sensitivity. However, a strongly nonlinear response combined with a high thermomechanical noise level limits the useful linear dynamic range of this type of device. We derive the equations governing this behavior and find a strong dependence [[proportional]dsqrt((d/L)[sup 5])] of the dynamic range on aspect ratio

    Quantum Structure of Space Near a Black Hole Horizon

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    We describe a midi-superspace quantization scheme for generic single horizon black holes in which only the spatial diffeomorphisms are fixed. The remaining Hamiltonian constraint yields an infinite set of decoupled eigenvalue equations: one at each spatial point. The corresponding operator at each point is the product of the outgoing and ingoing null convergences, and describes the scale invariant quantum mechanics of a particle moving in an attractive 1/X21/X^2 potential. The variable XX that is analoguous to particle position is the square root of the conformal mode of the metric. We quantize the theory via Bohr quantization, which by construction turns the Hamiltonian constraint eigenvalue equation into a finite difference equation. The resulting spectrum gives rise to a discrete spatial topology exterior to the horizon. The spectrum approaches the continuum in the asymptotic region.Comment: References added and typos corrected. 21 pages, 1 figur

    Einstein's equations and the chiral model

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    The vacuum Einstein equations for spacetimes with two commuting spacelike Killing field symmetries are studied using the Ashtekar variables. The case of compact spacelike hypersurfaces which are three-tori is considered, and the determinant of the Killing two-torus metric is chosen as the time gauge. The Hamiltonian evolution equations in this gauge may be rewritten as those of a modified SL(2) principal chiral model with a time dependent `coupling constant', or equivalently, with time dependent SL(2) structure constants. The evolution equations have a generalized zero-curvature formulation. Using this form, the explicit time dependence of an infinite number of spatial-diffeomorphism invariant phase space functionals is extracted, and it is shown that these are observables in the sense that they Poisson commute with the reduced Hamiltonian. An infinite set of observables that have SL(2) indices are also found. This determination of the explicit time dependence of an infinite set of spatial-diffeomorphism invariant observables amounts to the solutions of the Hamiltonian Einstein equations for these observables.Comment: 22 pages, RevTeX, to appear in Phys. Rev.

    Novel neutron decay mode inside neutron stars

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    We explore the suggestion that the neutron lifetime puzzle might be resolved by neutrons decaying into dark matter through the process, n \rightarrow \chi\chi\chi, with \chi having a mass one third of that of the neutron. In particular, we examine the consequences of such a decay mode for the properties of neutron stars. Unlike an earlier suggested decay mode, in order to satisfy the constraints on neutron star mass and tidal deformability, there is no need for a strong repulsive force between the dark matter particles. This study suggests the possibility of having hot dark matter at the core of the neutron star and presents a possible mechanism of dark matter cooling, and examines the possible signal of neutrons decaying in this way inside the neutron star right after its birth.Comment: 5 figure

    Possible nature of Dark Matter

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    {We present a study of neutron star models that contain dark matter (DM) in the core. The DM is assumed to have a particle nature and to be self-interacting. Using constraints on the mass and radius of neutron stars, we investigate the allowed properties of either bosonic or fermionic DM particles. We consider cases where it constitutes up to 15\% of the mass of the star, even though conventional mechanisms cannot generate such large fractions. For this purpose three different models of neutron stars are considered, the first involving nucleons only, the second including hyperons, and the last involving strange matter in the core. Different EoSs are constructed for the various cases of fermionic and bosonic DM. These EoSs are solved for selected properties of the DM particles and the results are tested against mass, radius and tidal deformability constraints for neutron stars. The distribution of energy density of DM and ordinary matter inside the neutron stars is also presented. It is found that if the DM is fermionic in nature it does not just sit in the core but it is present everywhere in the star, from the centre to outside the surface and may even envelop it.Comment: 19 pages, 18 figure
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