3,554 research outputs found
Mean Field Limit of a Behavioral Financial Market Model
In the past decade there has been a growing interest in agent-based
econophysical financial market models. The goal of these models is to gain
further insights into stylized facts of financial data. We derive the mean
field limit of the econophysical model by Cross, Grinfeld, Lamba and Seaman
(Physica A, 354) and show that the kinetic limit is a good approximation of the
original model. Our kinetic model is able to replicate some of the most
prominent stylized facts, namely fat-tails of asset returns, uncorrelated stock
price returns and volatility clustering. Interestingly, psychological
misperceptions of investors can be accounted to be the origin of the appearance
of stylized facts. The mesoscopic model allows us to study the model
analytically. We derive steady state solutions and entropy bounds of the
deterministic skeleton. These first analytical results already guide us to
explanations for the complex dynamics of the model
Effects of Momentum Conservation and Flow on Angular Correlations at RHIC
Correlations of azimuthal angles observed at RHIC have gained great attention
due to the prospect of identifying fluctuations of parity-odd regions in the
field sector of QCD. Whereas the observable of interest related to parity
fluctuations involves subtracting opposite-sign from same-sign correlations,
the STAR collaboration reported the same-sign and opposite-sign correlations
separately. It is shown here how momentum conservation combined with collective
elliptic flow contributes significantly to this class of correlations, though
not to the difference between the opposite- and same-sign observables. The
effects are modeled with a crude simulation of a pion gas. Though the
simulation reproduces the scale of the correlation, the centrality dependence
is found to be sufficiently different in character to suggest additional
considerations beyond those present in the pion gas simulation presented here.Comment: 13 papges, 2 figure
Effect of ELF e.m. fields on metalloprotein redox-active sites
The peculiarity of the distribution and geometry of metallic ions in enzymes
pushed us to set the hypothesis that metallic ions in active-site act like tiny
antennas able to pick up very feeble e.m. signals. Enzymatic activity of Cu2+,
Zn2+ Superoxide Dismutase (SOD1) and Fe2+ Xanthine Oxidase (XO) has been
studied, following in vitro generation and removal of free radicals. We
observed that Superoxide radicals generation by XO is increased by a weak field
having the Larmor frequency fL of Fe2+ while the SOD1 kinetics is sensibly
reduced by exposure to a weak field having the frequency fL of Cu2+ ion.Comment: 18 pages, 4 figure
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