265 research outputs found
Power-law distribution in Japanese racetrack betting
Gambling is one of the basic economic activities that humans indulge in. An
investigation of gambling activities provides deep insights into the economic
actions of people and sheds lights on the study of econophysics. In this paper
we present an analysis of the distribution of the final odds of the races
organized by the Japan Racing Association. The distribution of the final odds
indicates a clear power law , where represents
the final odds. This power law can be explained on the basis of the assumption
that that every bettor bets his money on the horse that appears to be the
strongest in a race.Comment: to be published in Physica
Impurity-induced Ferromagnetism in Doped Triplet Excitonic Insulator
The theory of impurities in excitonic insulator is investigated in the light
of the recent experiments on hexaborides. First, we study the bound state
around the impurity and find that the bound state emerges when is
positive. Second, we study the continuum state using Abrikosov-Gor'kov's
approach. We find that the energy gap is reduced strongly when .
Finally, we solve Bogoliubov-de Gennes equations for excitonic insulator
numerically. We get the results consistent with the analytic ones.
We also find that incomplete ferromagnetism appears in doped triplet
excitonic insulator with impurity. We make a short qualitative discussion on
the ferromagnetism of doped hexaborides using our result.Comment: 9 pages, 9 EPS figures, submitted to PR
Bouchaud-M\'ezard model on a random network
We studied the Bouchaud-M\'ezard(BM) model, which was introduced to explain
Pareto's law in a real economy, on a random network. Using "adiabatic and
independent" assumptions, we analytically obtained the stationary probability
distribution function of wealth. The results shows that wealth-condensation,
indicated by the divergence of the variance of wealth, occurs at a larger
than that obtained by the mean-field theory, where represents the strength
of interaction between agents. We compared our results with numerical
simulation results and found that they were in good agreement.Comment: to be published in Physical Review
Time series analysis using persistent homology of distance matrix
The analysis of nonlinear dynamics is an important issue in numerous fields
of science. In this study, we propose a new method to analyze the time series
data using persistent homology (PH). The key idea is the application of PH to
the distance matrix. Using this method, we can obtain the topological features
embedded in the trajectories. We apply this method to the logistic map,
R\"ossler system, and electrocardiogram data. The results reveal that our
method can effectively identify nonlocal characteristics of the attractor and
can classify data based on the amount of noise.Comment: To be published in IEICE Nonlinear Theory and its Applicatio
The nature of the silicaphilic fluorescence of PDMPO
PDMPO (2-(4-pyridyl)-5-((4-(2-dimethylaminoethylaminocarbamoyl)methoxy)phenyl)oxazole), has unique silica specific fluorescence and is used in biology to understand biosilicification. This ‘silicaphilic’ fluorescence is not well understood nor is the response to local environmental variables like solvent and pH. We investigated PDMPO in a range of environments: using UV-vis and fluorescence spectroscopy supported by computational data, (SPARC, molecular dynamics simulations, density functional theory calculations), dynamic light scattering and zeta potential measurements to understand the PDMPO–silica interaction. From absorption data, PDMPO exhibited a pKa of 4.20 for PDMPOH22+ to PDMPOH+ . Fluorescence emission measurements revealed large shifts in excited state pKa* values with different behaviour when bound to silica (pKa* of 10.4). PDMPO bound to silica particles is located in the Stern layer with the dye exhibiting pH dependent depolarising motion. In aqueous solution, PDMPO showed strong chromaticity with correlation between the maximum emission wavelength for PDMPOH+* and dielectric constant (4.8–80). Additional chromatic effects were attributed to changes in solvent accessible surface area. Chromatic effects were also observed for silica bound dye which allow its use as a direct probe of bulk pH over a range far in excess of what is possible for the dye alone (3–5.2). The unique combination of chromaticity and excited state dynamics allows PDMPO to monitor pH from 3 to 13 while also reporting on surface environment opening a new frontier in the quantitative understanding of (bio)silicification
Uniform synchronous criticality of diversely random complex networks
We investigate collective synchronous behaviors in random complex networks of
limit-cycle oscillators with the non-identical asymmetric coupling scheme, and
find a uniform coupling criticality of collective synchronization which is
independent of complexity of network topologies. Numerically simulations on
categories of random complex networks have verified this conclusion.Comment: 8 pages, 4 figure
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