Yongduk Kim

Batalin-Tyutin quantization of the self-dual massive theory in three dimensions

We quantize the self-dual massive theory by using the Batalin-Tyutin Hamiltonian method, which systematically embeds a second class constraint system into a first class one in extended phase space by introducing new fields. Through this analysis we obtain simultaneously the Stueckelberg scalar term related to the explicit gauge-breaking effect and a new type of Wess-Zumino action related to the Chern-Simons term.

Open-loop fiber-optic gyroscope using intensity-modulated source and phase modulation.

A simple open-loop approach to a standard fiber-optic gyroscope that uses an intensity-modulated source is described. Direct readout of the Sagnac effect in an open-loop form is obtained by applying a sinusoidal modulation to the source and the phase modulator at the proper frequency, with the modulation depth of the source adjusted appropriately. Experimental results show good linearity over a wide dynamic range.

Two-mode fiber-optic resonant ring interferometer as a sensor

A fiber-optic resonant ring interferometer using a directional coupler was fabricated using a single-mode fiber. It is an unbalanced interferometer functioning on the optical path-length difference. We have measured the phase shift caused by temperature changes with this setup and can determine the direction of temperature variance when a light source of appropriate wavelength is used. Using a prism output coupler for an optical fiber in the resonant ring interferometer, we determine the intensity variation of the radiation pattern caused by the thermally induced phase shift.

Batalin-Tyutin Quantization of the Chern-Simons-Proca Theory

We quantize the Chern-Simons-Proca theory in three dimensions by using the Batalin-Tyutin Hamiltonian method, which systematically embeds second-class constraint system into first-class by introducing new fields in the extended phase space. As a result, we obtain simultaneously the Stuckelberg scalar term, which is needed to cancel the gauge anomaly due to the mass term, and the new type of Wess-Zumino action, which is irrelevant to the gauge symmetry. We also investigate the ir property of the Chern-Simons-Proca theory by using the Batalin-Tyutin formalism as compared to the symplectic formalism. As a result, we observe that the resulting theory is precisely the gauge-invariant Chern-Simons-Proca quantum-mechanical version of this theory.

Complete set of SU(5) monopole solutions

The manifestly nonsingular asymptotic forms of the most general possible pointlike SU(5) monopoles are found by using the magnetic symmetry introduced by Cho. New magnetic tensor representations greatly expedite the computations. These magnetic tensors explicitly exhibit the full homotopy class of the mappings classifying the arbitrary allowed magnetic charges.

ON THE ENTROPY OF MINIMALLY COUPLED AND NONMINIMALLY COUPLED GRAVITIES

We investigate whether the gravitational thermodynamic properties of the scalar-tensor theory of gravity are affected by the conformal transformation or not. As an explicit example, we consider an electrically charged static spherical black hole in four-dimensional low energy effective theory of bosonic string.

A novel method of measuring linewidth enhancement factor of a semiconductor laser with resonant optical feedback

Abstract A new method for the measurement of the linewidth enhancement factor of semiconductor lasers is proposed. This method is based on the fact that the frequency locking range of semiconductor lasers with resonant optical feedback depends on the linewidth enhancement factor and the feedback power coupling factor. The frequency locking range has been determined accurately from the transmission curve of a confocal Fabry-Perot cavity.

SUCCESSIVE SUPERALGEBRAIC TRUNCATIONS FROM THE MAXIMAL SUPERGRAVITY IN FOUR DIMENSIONS

We study the four-dimensional N=8 maximal supergravity in the context of Lie superalgebra SU(8/1). All possible successive superalgebraic truncations from fourdimensional N=8 theory to N=7, 6, · · ·, 1 supergravity theories are systematically realized as sub-superalgebra chains of SU(8/1) by using the Kac-Dynkin weight techniques. PACS Nos: 04.65.+e, 11.30.Pb ∗ E-mail address : yjpark@ccs.sogang.ac.kr

Energy spectrum of the total system for a NQR experiment

Abstract We obtain the effective propagator and the semiclassical quantization rule for the external system in two adiabatically interacting systems, which accommodate the non-Abelian geometric phase of Wilczek and Zee. By using this formalism we calculate the energy spectrum of the total system which consists of the internal spin quadropole and the external agent rotating the internal system.

PHYSICAL SPECTRUM OF CHIRAL SCHWINGER MODEL IN THE MATTER GAUGE

We study the physical spectrum and the fermionic operator solutions of the chiral Schwinger model and the minimal chiral Schwinger model in the matter gauge.