16,342 research outputs found
Entwined Pairs and Schroedinger 's Equation
We show that a point particle moving in space-time on entwined-pair paths
generates Schroedinger's equation in a static potential in the appropriate
continuum linit. This provides a new realist context for the Schroedinger
equation within the domain of classical stochastic processes. It also suggests
that self-quantizing systems may provide considerable insight into conventional
quantum mechanics.Comment: 16 pg. 1 fi
Entwined Paths, Difference Equations and the Dirac Equation
Entwined space-time paths are bound pairs of trajectories which are traversed
in opposite directions with respect to macroscopic time. In this paper we show
that ensembles of entwined paths on a discrete space-time lattice are simply
described by coupled difference equations which are discrete versions of the
Dirac equation. There is no analytic continuation, explicit or forced, involved
in this description. The entwined paths are `self-quantizing'. We also show
that simple classical stochastic processes that generate the difference
equations as ensemble averages are stable numerically and converge at a rate
governed by the details of the stochastic process. This result establishes the
Dirac equation in one dimension as a phenomenological equation describing an
underlying classical stochastic process in the same sense that the Diffusion
and Telegraph equations are phenomenological descriptions of stochastic
processes.Comment: 15 pages, 5 figures Replacement 11/02 contains minor editorial
change
The Fractal Universe
In this talk, we touch upon the chaotic and fractal aspects of the Universe.Comment: 5 pages, Te
From the Neutrino to the Edge of the Universe
Two recent findings necessitate a closer look at the existing standard models
of Particle Physics and Cosmology. These are the discovery of Neutrino
oscillation, and hence a non zero mass on the one hand and, on the other,
observations of distant supernovae which indicate that contrary to popular
belief, the universe would continue to expand for ever, possibly accelerating
in the process. In this paper it is pointed out that relatively recent studies
which indicate a stochastic, quantum vacuum underpinning and a fractal
structure for space time, reconcile both of the recent observations,
harmoniously.Comment: 15 pages, Te
Megaeventos esportivos: um olhar para além do espetáculo
Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014O presente trabalho consiste em um relato de experiência de bolsistas do Programa
Institucional de Bolsas de Iniciação à Docência (PIBID) de Educação Física, a partir da
implementação de um projeto pedagógico realizado no Colégio Estadual São Vicente de Paulo, na
cidade de Irati, Paraná. Este projeto de intervenção apresenta e discute a temática megaeventos
esportivos, com foco em alunos do primeiro ano do ensino médio. Espera-se que após oito aulas
relacionadas ao tema proposto, seja possível despertar um olhar curioso por parte dos alunos, afim de
que sejam capazes de compreender e posicionar-se sobre aspectos relacionados ao tema megaeventos
esportivos. Investir na discussão de conteúdos da Educação Física, relacionados ao cotidiano dos
alunos, pode contribuir para uma formação escolar comprometida com demandas sócio-educacionai
Outgassing of icy bodies in the solar system - I. The sublimation of hexagonal water ice through dust layers
Our knowledge about the physical processes determining the activity of comets
were mainly influenced by several extremely successful space missions, the
predictions of theoretical models and the results of laboratory experiments.
However, novel computer models should not be treated in isolation but should be
based on experimental results. Therefore, a new experimental setup was
constructed to investigate the temperature dependent sublimation properties of
hexagonal water ice and the gas diffusion through a dry dust layer covering the
ice surface. We show that this experimental setup is capable to reproduce known
gas production rates of pure hexagonal water ice. The reduction of the gas
production rate due to an additional dust layer on top of the ice surface was
measured and compared to the results of another experimental setup in which the
gas diffusion through dust layers at room temperature was investigated. We
found that the relative permeability of the dust layer is inversely
proportional to its thickness, which is also predicted by theoretical models.
However, the measured absolute weakening of the gas flow was smaller than
predicted by models. This lack of correspondence between model and experiment
may be caused by an ill-determination of the boundary condition in the
theoretical models, which further demonstrates the necessity of laboratory
investigations. Furthermore, the impedance of the dust layer to the ice
evaporation was found to be similar to the impedance at room temperature, which
means that the temperature profile of the dust layer is not influencing the
reduction of the gas production. Finally, we present the results of an extended
investigation of the sublimation coefficient, which is an important factor for
the description of the sublimation rate of water ice and, thus, an important
value for thermophysical modeling of icy bodies in the solar system.Comment: Submitted to Icaru
Issues and Ramifications in Quantized Fractal Space Time: An Interface with Quantum Superstrings
Recently a stochastic underpinning for space time has been considered, what
may be called Quantized Fractal Space Time. This leads us to a number of very
interesting consequences which are testable, and also provides a rationale for
several otherwise inexplicable features in Particle Physics and Cosmology.
These matters are investigated in the present paper.Comment: 27 pages, TeX, This is from the forthcoming book The Chaotic Univers
Solitons of the Resonant Nonlinear Schrodinger Equation with Nontrivial Boundary Conditions and Hirota Bilinear Method
Physically relevant soliton solutions of the resonant nonlinear Schrodinger
(RNLS) equation with nontrivial boundary conditions, recently proposed for
description of uniaxial waves in a cold collisionless plasma, are considered in
the Hirota bilinear approach. By the Madelung representation, the model is
transformed to the reaction-diffusion analog of the NLS equation for which the
bilinear representation, soliton solutions and their mutual interactions are
studied.Comment: 15 pages, 1 figure, talk presented in Workshop `Nonlinear Physics IV:
Theory and Experiment`, 22-30 June 2006, Gallipoli, Ital
Coherent states of non-Hermitian quantum systems
We use the Gazeau-Klauder formalism to construct coherent states of
non-Hermitian quantum systems. In particular we use this formalism to construct
coherent state of a PT symmetric system. We also discuss construction of
coherent states following Klauder's minimal prescription.Comment: to appear in Phys.Lett
Does biological relatedness affect child survival?
Objective: We studied child survival in Rakai, Uganda where many children are fostered out or orphaned. Methods: Biological relatedness is measured as the average of the Wright’s coefficients between each household member and the child. Instrumental variables for fostering include proportion of adult males in household, age and gender of household head. Control variables include SES, religion, polygyny, household size, child age, child birth size, and child HIV status. Results: Presence of both parents in the household increased the odds of survival by 28%. After controlling for the endogeneity of child placement decisions in a multivariate model we found that lower biological relatedness of a child was associated with statistically significant reductions in child survival. The effects of biological relatedness on child survival tend to be stronger for both HIV- and HIV+ children of HIV+ mothers. Conclusions: Reductions in the numbers of close relatives caring for children of HIV+ mothers reduce child survival.AIDS/HIV, child survival, fostering, orphans, Uganda
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