28,228 research outputs found
Triple Products and Yang-Baxter Equation (II): Orthogonal and Symplectic Ternary Systems
We generalize the result of the preceeding paper and solve the Yang-Baxter
equation in terms of triple systems called orthogonal and symplectic ternary
systems. In this way, we found several other new solutions.Comment: 38 page
AdS_3/CFT_2 Correspondence and Space-Time N=3 Superconformal Algebra
We study a Wess-Zumino-Witten model with target space AdS_3 x (S^3 x S^3 x
S^1)/Z_2. This allows us to construct space-time N=3 superconformal theories.
By combining left-, and right-moving parts through a GSO and a Z_2 projections,
a new asymmetric (N,\bar{N})=(3,1) model is obtained. It has an extra gauge
(affine) SU(2) symmetry in the target space of the type IIA string. An
associated configuration is realized as slantwise intersecting M5-M2 branes
with a Z_2-fixed plane in the M-theory viewpoint.Comment: 27 pages, 1 figure, final versio
Phase transition of color-superconductivity and cooling behavior of quark stars
We discuss the color-superconductivity and its effect on the cooling behavior
of strange quark stars. The neutrino emissivity and specific heat of quark
matter are calculated within the BCS theory. In the superconducting phase, the
emissivity decreases and causes suppression of the cooling rate. It is shown
that the phase transition leads to a sudden discontinuous suppression of the
cooling rate in cooperation with the specific heat.Comment: 7 pages, 3 figure
Black Strings in Our World
The brane world scenario is a new approach to resolve the problem on how to
compactify the higher dimensional spacetime to our 4-dimensional world. One of
the remarkable features of this scenario is the higher dimensional effects in
classical gravitational interactions at short distances. Due to this feature,
there are black string solutions in our 4-dimensional world. In this paper,
assuming the simplest model of complex minimally coupled scalar field with the
local U(1) symmetry, we show a possibility of black-string formation by merging
processes of type I long cosmic strings in our 4-dimensional world. No fine
tuning for the parameters in the model might be necessary.Comment: 11pages, no figur
Cooling of a Micro-mechanical Resonator by the Back-action of Lorentz Force
Using a semi-classical approach, we describe an on-chip cooling protocol for
a micro-mechanical resonator by employing a superconducting flux qubit. A
Lorentz force, generated by the passive back-action of the resonator's
displacement, can cool down the thermal motion of the mechanical resonator by
applying an appropriate microwave drive to the qubit. We show that this onchip
cooling protocol, with well-controlled cooling power and a tunable response
time of passive back-action, can be highly efficient. With feasible
experimental parameters, the effective mode temperature of a resonator could be
cooled down by several orders of magnitude.Comment: 10 pages, 4 figure
Spaces of polynomials with roots of bounded multiplicity
We describe an alternative approach to some results of Vassiliev on spaces of
polynomials, by using the scanning method which was used by Segal in his
investigation of spaces of rational functions. We explain how these two
approaches are related by the Smale-Hirsch Principle or the h-Principle of
Gromov. We obtain several generalizations, which may be of interest in their
own right.Comment: 29 pages, AMS-Te
Creep rupture of materials: insights from a fiber bundle model with relaxation
I adapted a model recently introduced in the context of seismic phenomena, to
study creep rupture of materials. It consists of linear elastic fibers that
interact in an equal load sharing scheme, complemented with a local
viscoelastic relaxation mechanism. The model correctly describes the three
stages of the creep process, namely an initial Andrade regime of creep
relaxation, an intermediate regime of rather constant creep rate, and a
tertiary regime of accelerated creep towards final failure of the sample. In
the tertiary regime creep rate follows the experimentally observed one over
time-to-failure dependence. The time of minimum strain rate is systematically
observed to be about 60-65 % of the time to failure, in accordance with
experimental observations. In addition, burst size statistics of breaking
events display a -3/2 power law for events close to the time of failure, and a
steeper decay for the all-time distribution. Statistics of interevent times
shows a tendency of the events to cluster temporarily. This behavior should be
observable in acoustic emission experiments
Numerical Computation of Thermoelectric and Thermomagnetic Effects
Phenomenological equations describing the Seebeck, Hall, Nernst, Peltier,
Ettingshausen, and Righi-Leduc effects are numerically solved for the
temperature, electric current, and electrochemical potential distributions of
semiconductors under magnetic field. The results are compared to experiments.Comment: 4 pages, 7 figures. Submitted to Proceedings of XVII International
Conference on Thermoelectrics (ICT98), 1998 Nagoya, Japa
- âŠ