22,309 research outputs found
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
Voltage-biased I-V characteristics in the multi-Josephson junction model of high T 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
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 -independent and the cancellation of the -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
Flight comparison of the transonic agility of the F-111A airplane and the F-111 supercritical wing airplane
A flight research program was conducted to investigate the improvements in maneuverability of an F-111A airplane equipped with a supercritical wing. In this configuration the aircraft is known as the F-111 TACT (transonic aircraft technology) airplane. The variable-wing-sweep feature permitted an evaluation of the supercritical wing in many configurations. The primary emphasis was placed on the transonic Mach number region, which is considered to be the principal air combat arena for fighter aircraft. An agility study was undertaken to assess the maneuverability of the F-111A aircraft with a supercritical wing at both design and off-design conditions. The evaluation included an assessment of aerodynamic and maneuver performance in conjunction with an evaluation of precision controllability during tailchase gunsight tracking tasks
Observations of IRAS F10214+4724 at the Nobeyama millimeter array
F10214+4724 is an IRAS source at z=2.286 with L(sub FIR) approximately 10(exp 14) solar luminosity. The CO(3-2) emission was detected at the NRAO 12-m telescope, and its molecular gas mass was estimated to be (1-3)x10(exp 11) solar mass. This object is unique and important because it is the first high-z object from which molecular line emission is detected and it enables us to investigate molecular gas content, star forming material, at an early stage of galactic evolution. If IRAS F10214+4724 is a primeval galaxy at the formation process, it is possible the gas has not been collapsed yet to the galactic scale. On the other hand, it is also possible IRAS F10214+4724 is a merging or interacting system like the most of ultra-luminous infrared galaxies. However, since the first detection was made with a medium size single-dish telescope, the precise position, extent, and distribution of the molecular gas had not been determined. The aim of our aperture synthesis observations is therefore to determine position and distribution of molecular gas
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