Topological Terms in String Theory on Orbifolds

We study toroidal orbifold models with topologically invariant terms in the path integral formalism and give physical interpretations of the terms from an operator formalism point of view. We briefly discuss a possibility of a new class of modular invariant orbifold models.Comment: 15pages,LaTex,KOBE-TH-94-0

Large Area Crop Inventory Experiment (LACIE). The Z-index and subitaneous events as variables for estimating wheat yields in Argentina

There are no author-identified significant results in this report

A New Mechanism of Spontaneous SUSY Breaking

We propose a new mechanism of spontaneous supersymmetry breaking. The existence of extra dimensions with nontrivial topology plays an important role. We investigate new features resulted from the mechanism in two simple supersymmetric Z_2 and U(1) models. One of remarkable features is that there exists a phase in which the translational invariance for the compactified directions is broken spontaneously, accompanying the breakdown of the supersymmetry. The mass spectrum of the models appeared in reduced dimensions is a full of variety, reflecting the highly nontrivial vacuum structure of the models. The Nambu-Goldstone bosons (fermions) associated with breakdown of symmetries are found in the mass spectrum. Our mechanism also yields quite different vacuum structures if models have different global symmetries.Comment: 43 pages, 3 figure

An extension of Fourier analysis for the n-torus in the magnetic field and its application to spectral analysis of the magnetic Laplacian

We solved the Schr{\"o}dinger equation for a particle in a uniform magnetic field in the n-dimensional torus. We obtained a complete set of solutions for a broad class of problems; the torus T^n = R^n / {\Lambda} is defined as a quotient of the Euclidean space R^n by an arbitrary n-dimensional lattice {\Lambda}. The lattice is not necessary either cubic or rectangular. The magnetic field is also arbitrary. However, we restrict ourselves within potential-free problems; the Schr{\"o}dinger operator is assumed to be the Laplace operator defined with the covariant derivative. We defined an algebra that characterizes the symmetry of the Laplacian and named it the magnetic algebra. We proved that the space of functions on which the Laplacian acts is an irreducible representation space of the magnetic algebra. In this sense the magnetic algebra completely characterizes the quantum mechanics in the magnetic torus. We developed a new method for Fourier analysis for the magnetic torus and used it to solve the eigenvalue problem of the Laplacian. All the eigenfunctions are given in explicit forms.Comment: 32 pages, LaTeX, minor corrections are mad

Gauge-Fixing and Residual Symmetries in Gauge/Gravity Theories with Extra Dimensions

We study compactified pure gauge/gravitational theories with gauge-fixing terms and show that these theories possess quantum mechanical SUSY-like symmetries between unphysical degrees of freedom. These residual symmetries are global symmetries and generated by quantum mechanical N=2 supercharges. Also, we establish new one-parameter family of gauge choices for higher-dimensional gravity, and calculate as a check of its validity one graviton exchange amplitude in the lowest tree-level approximation. We confirm that the result is indeed $\xi$-independent and the cancellation of the $\xi$-dependence is ensured by the residual symmetries. We also give a simple interpretation of the vDVZ-discontinuity, which arises in the lowest tree-level approximation, from the supersymmetric point of view.Comment: REVTeX4, 17 pages, 1 figur

Voltage-biased I-V characteristics in the multi-Josephson junction model of high Tc_c superconductor

By use of the multi-Josephson junction model, we investigate voltage-biased I-V characteristics. Differently from the case of the single junction, I-V characteristics show a complicated behavior due to inter-layer couplings among superconducting phase differences mediated by the charging effect. We show that there exist three characteristic regions, which are identified by jumps and cusps in the I-V curve. In the low voltage region, the total current is periodic with trigonometric functional increases and rapid drops. Then a kind of chaotic region is followed. Above certain voltage, the total current behaves with a simple harmonic oscillation and the I-V characteristics form a multi-branch structure as in the current-biased case. The above behavior is the result of the inter-layer coupling, and may be used to confirm the inter-layer coupling mechanism of the formation of hysteresis branches.Comment: 12 pages, Latex, 4 figure

Rotating Boson Star with Large Self-interaction in (2+1) dimensions

Solutions for rotating boson stars in (2+1) dimensional gravity with a negative cosmological constant are obtained numerically. The mass, particle number, and radius of the (2+1) dimensional rotating boson star are shown. Consequently we find the region where the stable boson star can exist.Comment: 14 pages, 6 figures, RevTe