5,081 research outputs found
Renormalization analysis of catalytic Wright-Fisher diffusions
Recently, several authors have studied maps where a function, describing the
local diffusion matrix of a diffusion process with a linear drift towards an
attraction point, is mapped into the average of that function with respect to
the unique invariant measure of the diffusion process, as a function of the
attraction point. Such mappings arise in the analysis of infinite systems of
diffusions indexed by the hierarchical group, with a linear attractive
interaction between the components. In this context, the mappings are called
renormalization transformations. We consider such maps for catalytic
Wright-Fisher diffusions. These are diffusions on the unit square where the
first component (the catalyst) performs an autonomous Wright-Fisher diffusion,
while the second component (the reactant) performs a Wright-Fisher diffusion
with a rate depending on the first component through a catalyzing function. We
determine the limit of rescaled iterates of renormalization transformations
acting on the diffusion matrices of such catalytic Wright-Fisher diffusions.Comment: 65 pages, 3 figure
Antiproton-proton partial-wave analysis below 925 MeV/c
A partial-wave analysis of all antiproton-proton scattering data below 925
MeV/c antiproton laboratory momentum is presented. The method used is adapted
from the Nijmegen phase-shift analyses of pp and np scattering data. The
Nijmegen 1993 antiproton-proton database, consisting of 3646 antiproton-proton
scattering data, is presented and discussed. The best fit to this database
results in chi^2_min/Ndata = 1.043. The pseudovector coupling constant of the
charged pion to nucleons is determined to be (f_c)^2 = 0.0732(11) at the pion
pole, where the error is statistical.Comment: Report THEF-NYM 93.02 42 pages REVTeX, 7 separate postscript figures
appended. Accepted for publication in Phys. Rev.
Deuteron Dipole Polarizabilities and Sum Rules
The scalar, vector, and tensor components of the (generalized) deuteron
electric polarizability are calculated, as well as their logarithmic
modifications. Several of these quantities arise in the treatment of the
nuclear corrections to the deuterium Lamb shift and the deuterium hyperfine
structure. A variety of second-generation potential models are used and a
(subjective) error is assigned to the calculations. The zero-range
approximation is used to analyze a subset of the results, and a simple
relativistic version of this approximation is developed.Comment: 14 pages, LaTex - submitted to Physical Review
Racism and racial categorization.
Social identity theory predicts that perceivers strongly identified with an in-group will maximize the distinction and maintain a clear boundary between their own and other groups by categorizing others' membership accurately. Two experiments tested the prediction that racially prejudiced individuals, who presumably identify highly with their racial in-group, are more motivated to make accurate racial categorizations than nonprejudiced individuals. Results indicated that prejudiced participants not only took longer to categorize race-ambiguous targets (Experiments 1 and 2), but also made more nonverbal vocalizations when presented with them (Experiment 1), suggesting response hesitation. The results support the hypothesis that, compared to nonprejudiced individuals, prejudiced individuals concern themselves with accurate identification of in-group and out-group members and use caution when making racial categorizations
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