36,780 research outputs found
Observations of Ion Density and Temperature around the International Space Station During two Geomagnetic Storms
The International Space Station (ISS) is a low Earth orbit research facility and host to an international crew. Geomagnetic storms cause changes in the Earth’s magnetic field and affect the ion density and temperature in the ionosphere which could pose a hazard to ISS crew. This hazard is measured by the Floating Potential Measurement Unit (FPMU) which measures ion density, ion temperature, and the charge differential of the ISS relative to its surrounding environment. I analyzed data collected by Narrow Sweep Langmuir Probe for two storms in 2015. Ion density and temperature were affected by geomagnetic storms, but the effects were less than those found due to normal orbital conditions
Conceptualising rural-urban dynamics
This paper revisits the work of Richard Cantillon and Francois Quesnay in order to conceptualise the dynamics between rural and urban areas in an economy. Concepts of social surplus and economy as a circular flow are presented in order to highlight the interrelationship between the growth processes in the rural as well as urban areas. The paper concludes by pointing out the significance of the works of Cantillon and Quesnay.Economic growth; Cantillon; Quesnay; Urban; Rural
Economists, listen to Feyerabend
This paper revisits the writings of the philosopher of science, Paul Feyerabend, in order to argue for pluralism in economics education. In particular, the benefits of pluralism, the role of science and the notion of scientific rationality are examined from the perspective of economics.Feyerabend, Economics teaching, Pluralism
On symmetric continuum opinion dynamics
This paper investigates the asymptotic behavior of some common opinion
dynamic models in a continuum of agents. We show that as long as the
interactions among the agents are symmetric, the distribution of the agents'
opinion converges. We also investigate whether convergence occurs in a stronger
sense than merely in distribution, namely, whether the opinion of almost every
agent converges. We show that while this is not the case in general, it becomes
true under plausible assumptions on inter-agent interactions, namely that
agents with similar opinions exert a non-negligible pull on each other, or that
the interactions are entirely determined by their opinions via a smooth
function.Comment: 28 pages, 2 figures, 3 file
Violation of the holographic bulk viscosity bound
Motivated by gauge theory/string theory correspondence, a lower bound on the
bulk viscosity of strongly coupled gauge theory plasma was proposed in
arXiv:0708.3459. We consider strongly coupled N=4 supersymmetric Yang-Mills
plasma compactified on a two-manifold of constant curvature beta. We show that
the effective (1+1)-dimensional hydrodynamic description of the system is
governed by the bulk viscosity violating the bound of arXiv:0708.3459, once
beta<0.Comment: 17 pages, 3 figure
Replica Treatment of the Calogero-Sutherland Model
Employing Forrester-Ha method of Jack polynomials, we derive an integral
identity connecting certain N-fold coordinate average of the
Calogero-Sutherland model with the n-fold replica integral. Subsequent
analytical continuation to non-integer n leads to asymptotic expressions for
the (static and dynamic) density-density correlation function of the model as
well as the Green's function for an arbitrary coupling constant .Comment: 15 pages, 3 figures, revised version, section 5 corrected, submitted
to Nucl.Phys.
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