Instabilities and propagation of neutrino magnetohydrodynamic waves in arbitrary direction

In a previous work [16], a new model was introduced, taking into account the role of the Fermi weak force due to neutrinos coupled to magnetohydrodynamic plasmas. The resulting neutrino-magnetohydrodynamics was investigated in a particular geometry associated with the magnetosonic wave, where the ambient magnetic field and the wavevector are perpendicular. The corresponding fast, short wavelength neutrino beam instability was then obtained in the context of supernova parameters. The present communication generalizes these results, allowing for arbitrary direction of wave propagation, including fast and slow magnetohydrodynamic waves and the intermediate cases of oblique angles. The numerical estimates of the neutrino-plasma instabilities are derived in extreme astrophysical environments where dense neutrino beams exist

Frobenius theorem and invariants for Hamiltonian systems

We apply Frobenius integrability theorem in the search of invariants for one-dimensional Hamiltonian systems with a time-dependent potential. We obtain several classes of potential functions for which Frobenius theorem assures the existence of a two-dimensional foliation to which the motion is constrained. In particular, we derive a new infinite class of potentials for which the motion is assurately restricted to a two-dimensional foliation. In some cases, Frobenius theorem allows the explicit construction of an associated invariant. It is proven the inverse result that, if an invariant is known, then it always can be furnished by Frobenius theorem

Manufacturing checkout of orbital operational stages Midterm report, period ending 24 Feb. 1965

Manufacturing checkout of orbital operational Saturn S-IVB stage and instrument unit for parking orbit operation

Fluid moment hierarchy equations derived from gauge invariant quantum kinetic theory

The gauge invariant electromagnetic Wigner equation is taken as the basis for a fluid-like system describing quantum plasmas, derived from the moments of the gauge invariant Wigner function. The use of the standard, gauge dependent Wigner function is shown to produce inconsistencies, if a direct correspondence principle is applied. The propagation of linear transverse waves is considered and shown to be in agreement with the kinetic theory in the long wavelength approximation, provided an adequate closure is chosen for the macroscopic equations. A general recipe to solve the closure problem is suggested.Comment: 12 pages, 1 figur

Trust in the US-EU fruit and vegetable chain: Do US exporters understand EU importers?

Research on organizational and inter organizational trust has become an important field in management and marketing literature, as it is perceived as a pivotal aspect of business transactions. However, clarifications are still needed on the issue of whom we trust; is the person whom we are trading with trusted, or the organization, or just the product‐quality? Not only has this question not been answered within this field of research, neither have cultural differences have been described to any great extent. Additionally, if the perceived factors important to establish trusting relationships may or may not be the same on the buyers and the sellers side in international business transaction in food chains. The primary objective of this research study therefore is to identify how well US exporters understand the elements of trust that establish strong relationships with EU importers. The Analytical Hierarchy Process was used to evaluate the importance of different trust elements in interviews conducted with US exporters and EU importers of fruits and vegetables. Results are compared, providing both a picture of the important facets of trust, as well as whether the partners understand the perspectives of the other partner

Market dynamics associated with credit ratings: a literature review.

Credit ratings produced by the major credit rating agencies (CRAs) aim to measure the creditworthiness, or more specifically the relative creditworthiness of companies, i.e. their ability to meet their debt servicing obligations. In principle, the rating process focuses on the fundamental long-term credit strength of a company. It is typically based on both public and private information, except for unsolicited ratings, which focus only on public information. The basic rationale for using ratings is to achieve information economies of scale and solve principal-agent problems. Partly for the same reasons, the role of credit ratings has expanded significantly over time. Regulators, banks and bondholders, pension fund trustees and other fiduciary agents have increasingly used ratings-based criteria to constrain behaviour. As a result, the influence of the opinions of CRAs on markets appears to have grown considerably in recent years. One aspect of this development is its potential impact on market dynamics (i.e. the timing and path of asset price adjustments, credit spreads, etc.), either directly, as a consequence of the information content of ratings themselves, or indirectly, as a consequence of the “hardwiring” of ratings into regulatory rules, fund management mandates, bond covenants, etc. When considering the impact of ratings and rating changes, two conclusions are worth highlighting. – First, ratings correlate moderately well with observed credit spreads, and rating changes with changes in spreads. However, other factors, such as liquidity, taxation and historical volatility clearly also enter into the determination of spreads. Recent research suggests that reactions to rating changes may also extend beyond the immediately-affected company to its peers, and from bond to equity prices. Furthermore, this price reaction to rating changes seems to be asymmetrical, i.e. more pronounced for downgrades than for upgrades, and may be more significant for equity prices than for bond prices. – Second, the hardwiring of regulatory and market rules, bond covenants, investment guidelines, etc., to ratings may influence market dynamics, and potentially lead to or magnify threshold effects. The more that different market participants adopt identical ratings-linked rules, or are subject to similar ratings-linked regulations, the more “spiky” the reaction to a credit event is likely to be. This reaction may include, in some cases, the emergence of severe liquidity pressures. Efforts have recently been made, notably with support from the rating agencies themselves, to encourage a more systematic disclosure of rating triggers and to renegotiate and smooth the possibly more destabilising forms of rating triggers. However, the lack of a clear disclosure regime makes it difficult to assess how far this process has evolved. Questions also remain as to the extent to which ratings-based criteria introduce a fundamentally new element into market behaviour, or, conversely, the extent to which they are simply a va riant of more traditional contractual covenants. Rating agencies strive to provide credit assessments that remain broadly stable through the course of the business cycle (rating “through the cycle”). Agencies and other analysts frequently contrast the fundamental credit analysis on which ratings are based with market sentiment — measured for example by bond spreads — which is arguably subject to more short-term influences. Agencies are adamant that they do not directly incorporate market sentiment into ratings (although they may use market prices as a diagnostic tool). On the contrary, they make every effort to exclude transient market sentiment. However, as reliance on ratings grows, CRAs are being increasingly expected to satisfy a widening range of constituencies, with different, and even sometimes conflicting, interests: issuers and “traditional” asset managers will look for more than a simple statement of near-term probability of loss, and will stress the need for ratings to exhibit some degree of stability over time. On the other hand, mark-to-market traders, active investors and risk managers may seek more frequent indications of credit changes. Hence, in the wake of major bankruptcies with heightened credit stress, rating agencies have been under considerable pressure to provide higher-frequency readings of credit status, without loss of quality. So far, they have responded to this challenge largely by adding more products to their traditional range, but also through modifications in the rating process. The rating process and the range of products offered by rating agencies have thus evolved over time, with, for instance, an increasing emphasis on the analysis of liquidity risks, a new focus on the hidden liabilities of companies and an increased use of market-based tools. It is too early, however, to judge whether these changes should simply be regarded as a refinement of the agencies’ traditional methodology or whether they suggest a more fundamental shift in the approach to credit risk measurement. For the same reason, it is not possible to draw any firm conclusions about changes in the effects of credit ratings on market dynamics.

Application of remote sensing to study nearshore circulation

The research to use remote sensing techniques for studying the continental shelf is reported. The studies reported include: (1) nearshore circulation in the vincinity of a natural tidal inlet; (2) identification of indicators of biological activity; (3) remote navigation system for tracking free drifting buoys; (4) experimental design of an estuaring tidal circulation; and (5) Skylab support work

Using the J1-J2 Quantum Spin Chain as an Adiabatic Quantum Data Bus

This paper investigates numerically a phenomenon which can be used to transport a single q-bit down a J1-J2 Heisenberg spin chain using a quantum adiabatic process. The motivation for investigating such processes comes from the idea that this method of transport could potentially be used as a means of sending data to various parts of a quantum computer made of artificial spins, and that this method could take advantage of the easily prepared ground state at the so called Majumdar-Ghosh point. We examine several annealing protocols for this process and find similar result for all of them. The annealing process works well up to a critical frustration threshold.Comment: 14 pages, 13 figures (2 added), revisions made to add citations and additional discussion at request of referee