SU(N) Coherent States

We generalize Schwinger boson representation of SU(2) algebra to SU(N) and define coherent states of SU(N) using $2(2^{N-1}-1)$ bosonic harmonic oscillator creation and annihilation operators. We give an explicit construction of all (N-1) Casimirs of SU(N) in terms of these creation and annihilation operators. The SU(N) coherent states belonging to any irreducible representations of SU(N) are labelled by the eigenvalues of the Casimir operators and are characterized by (N-1) complex orthonormal vectors describing the SU(N) manifold. The coherent states provide a resolution of identity, satisfy the continuity property, and possess a variety of group theoretic properties.Comment: 25 pages, LaTex, no figure

Entangled Husimi distribution and Complex Wavelet transformation

Based on the proceding Letter [Int. J. Theor. Phys. 48, 1539 (2009)], we expand the relation between wavelet transformation and Husimi distribution function to the entangled case. We find that the optical complex wavelet transformation can be used to study the entangled Husimi distribution function in phase space theory of quantum optics. We prove that the entangled Husimi distribution function of a two-mode quantum state |phi> is just the modulus square of the complex wavelet transform of exp{-(|eta|^2)/2} with phi(eta)being the mother wavelet up to a Gaussian function.Comment: 7 page

Coherent States with SU(N) Charges

We define coherent states carrying SU(N) charges by exploiting generalized Schwinger boson representation of SU(N) Lie algebra. These coherent states are defined on $2 (2^{N - 1} - 1)$ complex planes. They satisfy continuity property and provide resolution of identity. We also exploit this technique to construct the corresponding non-linear SU(N) coherent states.Comment: 18 pages, LaTex, no figure

Transition of amorphous to crystalline oxide film in initial oxide overgrowth on liquid metals

It is important to understand the mechanism of oxidation in the initial stage on the free surface of liquid metals. Mittemeijer and co-workers recently developed a thermodynamic model to study the oxide overgrowth on a solid metal surface. Based on this model, we have developed a thermodynamic model to analyse the thermodynamic stability of oxide overgrowth on liquid metals. The thermodynamic model calculation revealed that the amorphous oxide phase is thermodynamically preferred up to 1.3 and 0.35 nm respectively, in the initial oxide overgrowth on liquid Al and Ga at the corresponding melting point. However, the amorphous phase is thermodynamically unstable in the initial oxide overgrowth on liquid Mg. The thermodynamic stability of amorphous phase in the Al and Ga oxide systems is attributed to lower sums of surface and interfacial energies for amorphous phases, compared to that of the corresponding crystalline phases.Financial support under grant EP/H026177/1 from the EPSRC was used

Home country effects of offshoring. A critical survey on empirical literature.

The International fragmentation of production processes is of rising importance. One part of this fragmentation involves the relocation of a production process from a home- to a new host country. This literature survey deals with the effects of such relocations on the home country. First of all, we try to conceptualize the terms and definitions most frequently used in this context which are "outsourcing", "offshore outsourcing" and "offshoring". Despite the fact that there is little textual documentation dealing directly with the phenomena of offshoring and offshore outsourcing we try to give an overview of possible empirical literature to which one can regard to. Including FDI literature we try to cover empirical literature which can provide helpful insight on the effects of a relocation to foreign countries on the home country in connection with wages, skill upgrading, prices, profits, taxes and unions. (author's abstract)Series: Discussion Papers SFB International Tax Coordinatio

Generalized thermo vacuum state derived by the partial trace method

By virtue of the technique of integration within an ordered product (IWOP) of operators we present a new approach for deriving generalized thermo vacuum state which is simpler in form that the result by using the Umezawa-Takahashi approach, in this way the thermo field dynamics can be developed. Applications of the new state are discussed.Comment: 5 pages, no figure, revtex

Unified theory for Goos-H\"{a}nchen and Imbert-Fedorov effects

A unified theory is advanced to describe both the lateral Goos-H\"{a}nchen (GH) effect and the transverse Imbert-Fedorov (IF) effect, through representing the vector angular spectrum of a 3-dimensional light beam in terms of a 2-form angular spectrum consisting of its 2 orthogonal polarized components. From this theory, the quantization characteristics of the GH and IF displacements are obtained, and the Artmann formula for the GH displacement is derived. It is found that the eigenstates of the GH displacement are the 2 orthogonal linear polarizations in this 2-form representation, and the eigenstates of the IF displacement are the 2 orthogonal circular polarizations. The theoretical predictions are found to be in agreement with recent experimental results.Comment: 15 pages, 3 figure