Gauge Invariant Formulation and Bosonisation of the Schwinger Model

The functional integral of the massless Schwinger model in $(1+1)$ dimensions is reduced to an integral in terms of local gauge invariant quantities. It turns out that this approach leads to a natural bosonisation scheme, yielding, in particular the famous `bosonisation rule'' and giving some deeper insight into the nature of the bosonisation phenomenon. As an application, the chiral anomaly is calculated within this formulation.Comment: LaTeX, 8 page

Thinking about engaging North Korea: A study on the framing of the U.S. human rights public discourse in the Washington Post and New York Times between 2001 and 2017

North Korea said in January 2019 that it was exploring ways to engage the human rights issue. This was a much welcomed announcement because the issue must be addressed in order for the two countries to reach a formal, comprehensive peace agreement and the lifting or easing of unilateral sanctions. This study utilizes framing as an analytical tool to examine how the North Korean human rights discourse is framed in the United States for the purpose of identifying the salient rights‐based issues covered in two traditional media outlets, namely, the Washington Post and New York Times. Next, it reframes the discourse using a coding schema based on the convergence of the human rights, human security, and non‐traditional security discourses. A reframing of the discourse highlights how the universalist–particularist debate in the traditional rights‐based literature masks the underlying issues of the rights problem. A combination of the traditional rights‐based discourse and the masking of the issues contributes to a disconnect in the way in which North Korea has been engaged in the past. Therefore, a reframing of the discourse using the convergence of the human rights, human security, and non‐traditional security discourses could open new pathways for engagement

A new class of entanglement measures

We introduce new entanglement measures on the set of density operators on tensor product Hilbert spaces. These measures are based on the greatest cross norm on the tensor product of the sets of trace class operators on Hilbert space. We show that they satisfy the basic requirements on entanglement measures discussed in the literature, including convexity, invariance under local unitary operations and non-increase under local quantum operations and classical communication.Comment: Revised version accepted by J Math Phys, 12 pages, LaTeX, contains Sections 1-5 & 7 of the previous version. The previous Section 6 is now in quant-ph/0105104 and the previous Section 8 is superseded by quant-ph/010501

A Lattice Gauge Model of Singular Marsden-Weinstein Reduction. Part I. Kinematics

The simplest nontrivial toy model of a classical SU(3) lattice gauge theory is studied in the Hamiltonian approach. By means of singular symplectic reduction, the reduced phase space is constructed. Two equivalent descriptions of this space in terms of a symplectic covering as well as in terms of invariants are derived.Comment: 27 pages, 6 figure

The applicability of MFD thrusters to satellite power systems

The high power self field MPD thruster uses electromagnetic forces rather than electrostatic to accelerate a neutral plasma. The most attractive application of MPD thrusters to satellite power systems is in the area of electric propulsion for a cargo orbit transfer vehicle (COTV). Calculations were performed in order to compare the performance of a COTV using an ion or MPD propulsion system. Results show that the MPD propulsion system gives a shorter trip time with the same power and payload when compared to the ion thruster propulsion system at either value of specific impulse. More important than the trip time benefit may be the advantage a MPD propulsion system provides in system simplicity. Another interesting COTV concept using MPD thrusters is the use of a remote power supply located on the Earth, at GEO, or somewhere in between to transmit power to the COTV in a microwave transmission. The specific impulse at thrust levels of tens of newtons makes a MPD propulsion system a candidate for stationkeeping and attitude control of large space structures such as a SPS