Notes on Spinoptics in a Stationary Spacetime

In arXiv:1105.5629, equations of the modified geometrical optics for circularly polarized photon trajectories in a stationary spacetime are derived by using a (1+3)-decomposed form of Maxwell's equations. We derive the same results by using a four-dimensional covariant description. In our procedure, the null nature of the modified photon trajectory naturally appears and the energy flux is apparently null. We find that, in contrast to the standard geometrical optics, the inner product of the stationary Killing vector and the tangent null vector to the modified photon trajectory is no longer a conserved quantity along light paths. This quantity is furthermore different for left and right handed photon. A similar analysis is performed for gravitational waves and an additional factor of 2 appears in the modification due to the spin-2 nature of gravitational waves.Comment: 15 pages, to appear in PR

Long-Wavelength Excesses in Two Highly Obscured High-Mass X-Ray Binaries: IGR J16318–4848 and GX 301–2

We present evidence for excess long-wavelength emission from two high-mass X-ray binaries, IGR J16318-4848 and GX 301-2, that show enormous obscuration (N_H ≃ 10^(23)-10^(24) cm^(-2)) in their X-ray spectra. Using archival near- and mid-infrared data, we show that the spectral energy distributions of IGR J16318-4848 and GX 301-2 are substantially higher in the mid-infrared than their expected stellar emission. We successfully fit the excesses with ~1000 K blackbodies, which suggests that they are due to warm circumstellar dust that also gives rise to the X-ray absorption. However, we need further observations to constrain the detailed properties of the excesses. This discovery highlights the importance of mid-infrared observations for understanding highly obscured X-ray binaries

World Agriculture Organization (WAO): New Global Governance for Agricultural Trade

It is increasingly questionable whether the WTO regime is the most appropriate form of governance for addressing global problems related to agriculture. In particular, climate change, sustainability, hunger/poverty in developing countries, and expected imbalance in food demand-supply by 2050 are emerging as grave challenges to humanity and the WTO is still struggling to resolve issues (related to the multifunctional roles of agriculture) of the 20th century while completely lacking the capacity to tackle such new global issues of the 21st century. Given this outmoded institution, the primary objective of this article is to propose that a new system of governance is needed so as to exclusively and effectively deal with problems arising from the interactions among climate change, agricultural sustainability, food security, and trade.Global public goods, climate change, sustainable agriculture, food security, WTO, agricultural trade, International Relations/Trade,

Quantum Hall Ferromagnets: Induced Topological term and electromagnetic interactions

The $\nu = 1$ quantum Hall ground state in materials like GaAs is well known to be ferromagnetic in nature. The exchange part of the Coulomb interaction provides the necessary attractive force to align the electron spins spontaneously. The gapless Goldstone modes are the angular deviations of the magnetisation vector from its fixed ground state orientation. Furthermore, the system is known to support electrically charged spin skyrmion configurations. It has been claimed in the literature that these skyrmions are fermionic owing to an induced topological Hopf term in the effective action governing the Goldstone modes. However, objections have been raised against the method by which this term has been obtained from the microscopics of the system. In this article, we use the technique of the derivative expansion to derive, in an unambiguous manner, the effective action of the angular degrees of freedom, including the Hopf term. Furthermore, we have coupled perturbative electromagnetic fields to the microscopic fermionic system in order to study their effect on the spin excitations. We have obtained an elegant expression for the electromagnetic coupling of the angular variables describing these spin excitations.Comment: 23 pages, Plain TeX, no figure

MB 745 Leading Development Programs in Mission

Text books: a. Conflict Mediation Across Cultures, by David Augsburger (310 pp) b. African Friends and Money Matters, by David Maranz (224 pp) c. Orality and Literacy, by Walter Ong (201 pp) d. None of These Diseases: The Bible’s Health Secrets for the 21st Century, Millennium Three Edition, by S.I. McMillen and David E. Stern (285 pp) e. Students choose 200 pp of reading in their area of interest related to development in mission. A book can be picked from the bibliography or a suggestion submitted to the professor for approval.https://place.asburyseminary.edu/syllabi/3930/thumbnail.jp