47 research outputs found
Current Oscillations, Interacting Hall Discs and Boundary CFTs
In this paper, we discuss the behavior of conformal field theories
interacting at a single point. The edge states of the quantum Hall effect (QHE)
system give rise to a particular representation of a chiral Kac-Moody current
algebra. We show that in the case of QHE systems interacting at one point we
obtain a ``twisted'' representation of the current algebra. The condition for
stationarity of currents is the same as the classical Kirchoff's law applied to
the currents at the interaction point. We find that in the case of two discs
touching at one point, since the currents are chiral, they are not stationary
and one obtains current oscillations between the two discs. We determine the
frequency of these oscillations in terms of an effective parameter
characterizing the interaction. The chiral conformal field theories can be
represented in terms of bosonic Lagrangians with a boundary interaction. We
discuss how these one point interactions can be represented as boundary
conditions on fields, and how the requirement of chirality leads to
restrictions on the interactions described by these Lagrangians. By gauging
these models we find that the theory is naturally coupled to a Chern-Simons
gauge theory in 2+1 dimensions, and this coupling is completely determined by
the requirement of anomaly cancellation.Comment: 32 pages, LateX. Uses amstex, amssymb. Typos corrected. To appear in
Int. J. Mod. Phys.
The impact of oil prices on soybeans commodity prices: asymmetric cointegration evidence
The increases in soybean commodity prices are attributed to increase in oil prices which have affected the prices of agricultural grains commodity products such as soybean oil price. The study investigates asymmetric relationship between soybeans commodity price and crude oil price using most recent data. In order to account for possible asymmetric effect of oil price on soybeans commodity price, the paper uses momentum threshold autoregressive (MTAR) models, developed by Enders and Siklos (2001). Empirical results reveal that soybeans commodity prices and crude oil prices are cointegrated and the adjustment process is asymmetric in MTAR-consistent result. Our findings confirm that increase in crude oil prices affects the soybeans commodity prices in an asymmetric ways. Specifically, soybeans commodity prices rise faster when crude oil price increases but there is no immediate offsetting effect when the crude oil prices decrease. In other words, the asymmetric effect of oil price-shocks is greater when oil price increases than when oil price decreases. Policymakers may use these results to design appropriate policies to curb the inflationary consequences of oil prices
Renegade Films, Defa Musicals, and the Genre Cinema: Heißer Sommer (Hot Summer, Joachim Hasler, 1968)
Semantic-based grid resource discovery and its integration with the grid service broker
Abstract: This paper addresses the need of semantic component in the grid environment to discover and describe the grid resources semantically. We propose semantic grid architecture by introducing a knowledge layer at the top of Gridbus broker architecture and thereby enabling broker to discover resources semantically. The semantic component in the knowledge layer enables semantic description of grid resources with the help of ontology template. The Ontology template has been created using Protégé-OWL editor for different types of computing resources in the grid environment. The Globus Toolkit’s MDS is used to gather grid resource information and Protégé-OWL libraries are used to dynamically create knowledge base of grid resources. Algernon inference engine is used for interacting with the knowledge base to discover suitable resources. 1