13,321 research outputs found
Edge-induced spin polarization in two-dimensional electron gas
We characterize the role of the spin-orbit coupling between electrons and the confining potential of the edge in nonequilibrium two-dimensional homogeneous electronic gas. We derive a simple analytical result for the magnitude of the current-induced spin polarization at the edge and prove that it is independent of the details of the confinement edge potential and the electronic density within realistic values of the parameters of the considered models. While the amplitude of the spin accumulation is comparable to the experimental values of extrinsic spin-Hall effect in similar samples, the spatial extent of edge-induced effect is restricted to the distances on the order of Fermi wavelength (similar to 10 nm)
Reform Redux: Measurement, Determinants and Reversals
What do we know about the effects of structural reforms? One main reason the answer may be “little†is inadequate measurement. In this paper we put forward improved measures of economic liberalization across countries over time. We show that structural reforms, carefully measured, follow richer dynamics (than those from existing indexes) which are very closely linked to the theoretical work. For example, we find FDI inflows reduce the likelihood of privatization reversals and labour strikes increase that of price liberalization reversals. We also find that our new measures, in standard specifications, have larger and more precisely estimated impacts on growth.Structural reforms, reform reversals, price liberalization, trade liberalization, privatization, political economy.
Exact and Quasi-exact Models of Strange Stars
We construct and compare a variety of simple models for strange stars,
namely, hypothetical self-bound objects made of a cold stable version of the
quark-gluon plasma. Exact, quasi-exact and numerical models are examined to
find the most economical description for these objects. A simple and successful
parametrization of them is given in terms of the central density, and many
differences among the models are explicitly shown and discussed.Comment: 20 pp. 15 figures, to appear in IJMP
Self-bound Interacting QCD Matter in Compact Stars
The quark gluon plasma (QGP) at zero temperature and high baryon number is a
system that may be present inside compact stars. It is quite possible that this
cold QGP shares some relevant features with the hot QGP observed in heavy ion
collisions, being also a strongly interacting system. In a previous work we
have derived from the QCD Lagrangian an equation of state (EOS) for the cold
QGP, which can be considered an improved version of the MIT bag model EOS.
Compared to the latter, our equation of state reaches higher values of the
pressure at comparable baryon densities. This feature is due to perturbative
corrections and also to non-perturbative effects. Here we apply this EOS to the
study of neutron stars, discussing the absolute stability of quark matter and
computing the mass-radius relation for self-bound (strange) stars. The maximum
masses of the sequences exceed two solar masses, in agreement with the recently
measured values of the mass of the pulsar PSR J1614-2230, and the corresponding
radii around 10-11 km
Properties of the intermediate type of gamma-ray bursts
Gamma-ray bursts can be divided into three groups ("short", "intermediate",
"long") with respect to their durations. The third type of gamma-ray bursts -
as known - has the intermediate duration. We show that the intermediate group
is the softest one. An anticorrelation between the hardness and the duration is
found for this subclass in contrast to the short and long groups.Comment: In Sixteenth Maryland Astrophysics Conferenc
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