615 research outputs found
The Energy of Scattering Solitons in the Ward Model
The energy density of a scattering soliton solution in Ward's integrable
chiral model is shown to be instantaneously the same as the energy density of a
static multi-lump solution of the \CP^3 sigma model. This explains the
quantization of the total energy in the Ward model.Comment: 12 pages, 2 figure
Monetary Policy, Risk-Taking, and Pricing: Evidence from a Quasi-Natural Experiment
We analyse the impact of monetary policy on bank risk-taking and pricing. Bolivia provides us with an excellent experimental setting to identify this impact. Its small economy is not synchronized with the US economy but its banking system is almost fully dollarized. Consequently the US federal funds rate is the appropriate measure of monetary policy. We study the impact of the federal funds rate on the riskiness and pricing of new bank loans granted in Bolivia between 1999 and 2003, a period of significant variation in the federal funds rate. We find robust evidence that a decrease in the US federal funds rate prior to loan origination raises the monthly probability of default on individual bank loans. We also find that initiating loans with a subprime credit rating or loans to riskier borrowers with current or past non-performance become more likely when the federal funds rate is low. However, loan spreads do not increase, seemingly even decrease, in changes in the probability of default. Hence banks do not seem to price the additional risk taken. Furthermore, banks with more liquid assets and less funds from foreign financial institutions take more risk when the federal funds rate is low, and reduce loan spreads more despite the additional risk they seemingly take.monetary policy;federal funds rate;lending standards;credit risk;subprime borrowers;duration analysis
Skyrmions, Rational Maps & Scaling Identities
Starting from approximate Skyrmion solutions obtained using the rational map
ansatz, improved approximate Skyrmions are constructed using scaling arguments.
Although the energy improvement is small, the change of shape clarifies whether
the true Skyrmions are more oblate or prolate.Comment: 13 pages, 3 figure
Stock prices and output growth: an examination of the credit channel
When stock market values fall, we know that investors expect lower economic growth in the future. But can stock market declines actually affect future growth? There is some evidence that they can-through the credit channel.Stock - Prices
Why and how to integrate non-standard linguistic varieties into education: Cypriot Greek in Cyprus and the UK
• Greek Cypriot education remains largely oriented towards promoting standard language ideologies and only accepts Standard Greek as the language of teaching and learning.
• Cypriot Greek, the students’ home variety, is still seen as an obstacle to academic achievement by teachers and educational authorities.
• Cypriot Greek needs to be integrated into policies and practices of teaching and learning both in Cyprus and in the UK’s Greek Cypriot community.
• This will:
o hone pupils’ awareness of different varieties;
o foster the development of their critical literacy;
o facilitate the acquisition of Standard Greek;
o counter negative perceptions, stereotypes and feelings of inferiority associated with the use of Cypriot Greek; and,
o aid in the maintenance and intergenerational transmission of Cypriot Greek as a heritage and community language in the UK.
• Teachers and learning activities should promote and cultivate:
o awareness and respect of the different varieties spoken in class, Cypriot Greek and Standard Greek; and,
o awareness of vocabulary and grammar in the contexts of use of the two varieties and their social meanings.
•This approach will ultimately change the way we view language and literacy learning
Reduced dynamics of Ward solitons
The moduli space of static finite energy solutions to Ward's integrable
chiral model is the space of based rational maps from \CP^1 to itself
with degree . The Lagrangian of Ward's model gives rise to a K\"ahler metric
and a magnetic vector potential on this space. However, the magnetic field
strength vanishes, and the approximate non--relativistic solutions to Ward's
model correspond to a geodesic motion on . These solutions can be compared
with exact solutions which describe non--scattering or scattering solitons.Comment: Final version, to appear in Nonlinearit
Non-trivial Soliton Scattering in Planar Integrable Systems
The behavior of solitons in integrable theories is strongly constrained by
the integrability of the theory, that is by the existence of an infinite number
of conserved quantities that these theories are known to possess. As a result
the soliton scattering of such theories are expected to be trivial (with no
change of direction, velocity or shape). In this paper we present an extended
review on soliton scattering of two spatial dimensional integrable systems
which have been derived as dimensional reductions of the self-dual
Yang-Mills-Higgs equations and whose scattering properties are highly
non-trivial.Comment: 25 pages + 9 Figures, Review Paper to appear in International Journal
of Modern Physics
Solutions of the Generic Non-Compact Weyl Equation
In this paper, solutions of the generic non-compact Weyl equation are
obtained. In particular, by identifying a suitable similarity transformation
and introducing a non-trivial change of variables we are able to implement
azimuthal dependence on the solutions of the diagonal non-compact Weyl
equation. We also discuss some open questions related to the construction of
infinite BPS monopole configurations.Comment: 12 pages, Latex. Few extra comments and a reference adde
Radon measurements along active faults in the Langadas Basin, northern Greece
A network of three radon stations has been established in the Langadas Basin, northern Greece for radon monitoring by various techniques in earthquake prediction studies. Specially made devices with plastic tubes including Alpha Tracketch Detectors (ATD) were installed for registering alpha particles from radon and radon decay products exhaled from the ground, every 2 weeks, by using LR-115, type II, non-strippable Kodak films, starting from December 1996. Simultaneous measurements started using Lucas cells alpha spectrometer for instantaneous radon measurements in soil gas, before and after setting ATDs at the radon stations. Continuous monitoring of radon gas exhaling from the ground started from the middle of August 1999 by using silicon diode detectors, which simultaneously register meteorological parameters, such as rainfall, temperature and barometric pressure. The obtained data were studied together with the data of seismic events, such as the magnitude, <i>M<sub>L</sub></i>, of earthquakes that occurred at the Langadas Basin during the period of measurements, as registered by the Laboratory of Geophysics, Aristotle University of Thessaloniki, in order to find out any association between them
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