1,957 research outputs found
Cluster Heat Bath Algorithm in Monte Carlo Simulations of Ising Models
We have proposed a cluster heat bath method in Monte Carlo simulations of
Ising models in which one of the possible spin configurations of a cluster is
selected in accordance with its Boltzmann weight. We have argued that the
method improves slow relaxation in complex systems and demonstrated it in an
axial next-nearest-neighbor Ising(ANNNI) model in two-dimensions.Comment: 10 pages, REVTeX, 2 figures, to appear in Phys.Rev.Let
Development of deep-sea drone by spherical ultrasonic motor
The world ocean occupies 70 % on the earth and the average sea depth is about 4,000 m. More than 80 percent of it has not been investigated precisely and the bottom shape of the sea has not been mapped. When doing resource-searching in the future, the precise maps must be required. So, the authors have developed a drone movable around 4,000 m deep sea to measure the bottom of the ocean. It is based on spheres, which includes cameras, batteries, some sensors and controllers. It can rotate a spherical rotor sensing widely to obtain the information about the bottom of the sea. At the first step of the research, the authors have made basic experiments of the motor’s performance in water. The authors have obtained the excellent results in maneuverability, temperature durability, and shock resistance of the motor
Confined Phase In The Real Time Formalism And The Fate Of The World Behind The Horizon
In the real time formulation of finite temperature field theories, one
introduces an additional set of fields (type-2 fields) associated to each field
in the original theory (type-1 field). In hep-th/0106112, in the context of the
AdS-CFT correspondence, Maldacena interpreted type-2 fields as living on a
boundary behind the black hole horizon. However, below the Hawking-Page
transition temperature, the thermodynamically preferred configuration is the
thermal AdS without a black hole, and hence there are no horizon and boundary
behind it. This means that when the dual gauge theory is in confined phase, the
type-2 fields cannot be associated with the degrees of freedom behind the black
hole horizon. I argue that in this case the role of the type-2 fields is to
make up bulk type-2 fields of classical closed string field theory on AdS at
finite temperature in the real time formalism.Comment: v2: cases divided into sections with more detailed explanations.
considerably enlarged with examples and a lot of figures. sec 4.1.2 for
general closed cut-out circuits and appendix A for a sample calculation newly
added. many minor corrections and clarifying comments. refs added. v3: refs
and related discussion added. 1+46 pages, 26 figures. published versio
The defect variance of random spherical harmonics
The defect of a function is defined as the
difference between the measure of the positive and negative regions. In this
paper, we begin the analysis of the distribution of defect of random Gaussian
spherical harmonics. By an easy argument, the defect is non-trivial only for
even degree and the expected value always vanishes. Our principal result is
obtaining the asymptotic shape of the defect variance, in the high frequency
limit. As other geometric functionals of random eigenfunctions, the defect may
be used as a tool to probe the statistical properties of spherical random
fields, a topic of great interest for modern Cosmological data analysis.Comment: 19 page
Measuring our universe from galaxy redshift surveys
Galaxy redshift surveys have achieved significant progress over the last
couple of decades. Those surveys tell us in the most straightforward way what
our local universe looks like. While the galaxy distribution traces the bright
side of the universe, detailed quantitative analyses of the data have even
revealed the dark side of the universe dominated by non-baryonic dark matter as
well as more mysterious dark energy (or Einstein's cosmological constant). We
describe several methodologies of using galaxy redshift surveys as cosmological
probes, and then summarize the recent results from the existing surveys.
Finally we present our views on the future of redshift surveys in the era of
Precision Cosmology.Comment: 82 pages, 31 figures, invited review article published in Living
Reviews in Relativity, http://www.livingreviews.org/lrr-2004-
Elucidating the photosynthetic responses in chlorophyll-deficient soybean (Glycine max, L.) leaf
Chlorophyll (Chl)-deficient plants can potentially increase global surface albedo of mono-cropping systems, and simultaneously maintain a similar photosynthetic efficiency by increasing light canopy penetration and thus lowering investment in pigments. However, some previous studies have shown that pale mutants might reduce productivity in field conditions. Such lower yields were suspected to be due to loss of photosynthetic efficiency at leaf level during light fluctuations as a consequence of reduced capacity and slower relaxation of non-photochemical quenching (NPQ) of Chl fluorescence. In this paper, we tested this hypothesis by comparing, CO2 assimilation (A), photosystem II (PSII) efficiency (ΦPSII), photochemical quenching and NPQ, electron transport rate (ETR) and fluorescence yield (Fyield) in a green soybean (Glycine max L.) cultivar (Eiko) and in a Chl-deficient (MinnGold) mutant under dynamically fluctuating light conditions. MinnGold had significantly slower induction of ETR and lower A and ETR than Eiko, but there was little difference in ΦPSII between the two genotypes, suggesting that the lower photosynthesis of MinnGold was mainly due to lower light energy absorption by a Chl-deficient leaf. The NPQ capacity was also smaller in MinnGold than in Eiko. As for the kinetics of the rapidly inducible component of NPQ, MinnGold showed slower induction, not relaxation, than Eiko. The combination of the effect of Chl-deficiency on lower photosynthesis, NPQ capacity and slower NPQ induction may explain the lower biomass accumulation of MinnGold in the field. Our physiological observations, combined with fluorescence kinetics, can serve as a basis to parameterize Chl content in modelling radiative transfer and photosynthesis for upscaling measures of plant and ecosystem productivity by a big leaf model
Cosmological Redshift Distortion of Correlation Functions as a Probe of the Density Parameter and the Cosmological Constant
We propose cosmological redshift-space distortion of correlation functions of
galaxies and quasars as a probe of both the density parameter and
the cosmological constant . In particular, we show that
redshift-space distortion of quasar correlation functions at can in
principle set a constraint on the value of . This is in contrast to
the popular analysis of galaxy correlation functions in redshift space which
basically determines , where is the bias parameter, but
is insensitive to . For specific applications, we present
redshift-space distortion of correlation functions both in cold dark matter
models and in power-law correlation function models, and discuss the extent to
which one can discriminate between the different models.Comment: 9 pages, 3 figures included. Accepted for Publication in ApJ Letter
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