Relativistic Generalization and Extension to the Non-Abelian Gauge Theory of Feynman's Proof of the Maxwell Equations

R.P. Feynman showed F.J. Dyson a proof of the Lorentz force law and the homogeneous Maxwell equations, which he obtained starting from Newton's law of motion and the commutation relations between position and velocity for a single nonrelativistic particle. We formulate both a special relativistic and a general relativistic versions of Feynman's derivation. Especially in the general relativistic version we prove that the only possible fields that can consistently act on a quantum mechanical particle are scalar, gauge and gravitational fields. We also extend Feynman's scheme to the case of non-Abelian gauge theory in the special relativistic context.Comment: 22 page

EFFECT OF FORCE PLATFORM SURFACE ON GROUND REACTION PEAK FORCE

Repeated running and walking at a preferred speed across the two alternative surface covers was the basis of a comparison of peak force measures. These were obtained using a polyflex surface mounted on two force platforms, within a polyflex track system, with those obtained with a metal surface interface. When both the first and second foot strikes were considered within a stride, measures of peak impact and peak propulsion were almost the same. Mean ±s.e. measures were 2.021±0.068 BW and of 2.620±0.033 BW respectively for the polyflex and 1.987±0.066 BW and 2.607±0.031 BW respectively for the metal cover at a running speed of 3.9±0.09ms-1. Peak braking forces did not differ significantly between the surface coves. In running, the 0.017m of polyflex on the 0.004m aluminium base plate did not significantly attenuate peak vertical forces or braking forces

The One Loop Effective Action of QED for a General Class of Electric Fields

We compute the effective action of QED at one loop order for an electric field which points in the $\hat{z}$ direction and depends arbitrarily upon the light cone time coordinate, $x^+ = (x^0 + x^3)/\sqrt{2}$. This calculation generalizes Schwinger's formula for the vacuum persistence probability in the presence of a constant electric field.Comment: 9 pages, LaTeX 2 epsilo

Phase transition at finite temperature in one dimension: Adsorbate ordering in Ba/Si(111)3x2

We demonstrate that the Ba-induced Si(111)3x2 reconstruction is a physical realization of a one-dimensional antiferromagnetic Ising model with long-range Coulomb interactions. Monte Carlo simulations performed on a corresponding Coulomb-gas model, which we construct based on density-functional calculations, reveal an adsorbate-ordering phase transition at finite temperature. We show numerically that this unusual one-dimensional phase transition should be detectable by low-energy electron diffraction.Comment: 11 pages + 4 figures. Surf. Sci. Lett. (in press

Are Nonrenormalizable Gauge Theories Renormalizable?

We raise the issue whether gauge theories, that are not renormalizable in the usual power-counting sense, are nevertheless renormalizable in the modern sense that all divergences can be cancelled by renormalization of the infinite number of terms in the bare action. We find that a theory is renormalizable in this sense if the {\em a priori} constraints that we impose on the form of the bare action correspond to the cohomology of the BRST transformations generated by the action. Recent cohomology theorems of Barnich, Brandt, and Henneaux are used to show that conventionally nonrenormalizable theories of Yang-Mills fields (such as quantum chromodynamics with heavy quarks integrated out) and/or gravitation are renormalizable in the modern sense.Comment: 28 pages, no figures. This is a plain LaTeX file. No special macros are needed. Numerous changes are made in the previous version, including added reference

GROUND REACTION FORCES OCCURING DURING THE DELIVERY STRIDE OF JAVELIN THROWING

Five male javelin throwers (mean ± SD: age 24 ± 3 years; height 1.83 ± 0.06 m; body weight 888 ± 117 N) performed outdoors. Two Kistler force platforms were mounted beneath an outdoor polyflex runway (0.017 m depth) with positioning adjustment for each subject's delivery stride length. For the back foot the mean (±SD) peak vertical ground reaction force was 2.31 ± 0.41 BW, and maximum total force was 2.36 ± 0.50 BW. For the front foot the mean peak vertical force was 5.63 ± 1.31 BW, the braking force was 4.50 ± 0.96 BW and maximum total force was 7.05 ± 1.57 BW. At the beginning of the delivery stride, when the back foot contacted the ground, the mean peak vertical loading rate was 115 ± 35 BW/s which was less than the front foot loading rate of 192 ± 64 BWs/s

Dynamical Equations of Spinning Particles: Feynman's Proof

In this letter, we discuss the extension of Feynman's derivation of the equation of motion to the case of spinning particles. We show that a spinning particle interacts only with the electromagnetic and gravitational fields. In the absence of the electromagnetic interactions, we rederive Papapetrou's equations for spinning particles in the background of the conformal gravity. We also find that the effect of spin coupled to non-constant electromagnetic fields leads to further corrections to the Lorentz force equations. Some discussions of these results are given at the end.Comment: 16pages, RU93-10-

Compliance to the CONSORT Statement on Participant Flow Diagrams in Infectious Disease Randomized Clinical Trials

Background: The Consolidated Standard of Reporting Trials (CONSORT) Guidelines were developed to support adequate reporting of randomized controlled trials (RCTs). Method: A systematic review was conducted including RCTs of infectious diseases published in the top general medical and infectious disease journals in 2010. The level of compliance to flow diagram and its association with the CONSORT endorsement by the journals were evaluated. Results: A total of 67 studies were included in the analysis and a half of the studies were HIV/AIDS RCTs. About 78% of the studies included the flow diagram and 66% of the studies described an intention-to-treat approach. However, explicit descriptions of the study populations were the most lacking during the follow-up stage. The journals that endorsed the CONSORT statement had significantly lower odds of including the CONSORT flow diagram as compared with non-endorsing journals (OR=0.144; 95% CI 0.036-0.575, p\u3c0.05). Conclusions: About one out of four published RCTs in the top medical- and infectious disease journals did not include the CONSORT diagram in 2010, and inconsistency in the reporting of the study population was observed. Clear and complete description of the attrition, especially on the follow-up process, can enhance valid interpretations of the findings by clinical pharmacists

Similarity Renormalization, Hamiltonian Flow Equations, and Dyson's Intermediate Representation

A general framework is presented for the renormalization of Hamiltonians via a similarity transformation. Divergences in the similarity flow equations may be handled with dimensional regularization in this approach, and the resulting effective Hamiltonian is finite since states well-separated in energy are uncoupled. Specific schemes developed several years ago by Glazek and Wilson and contemporaneously by Wegner correspond to particular choices within this framework, and the relative merits of such choices are discussed from this vantage point. It is shown that a scheme for the transformation of Hamiltonians introduced by Dyson in the early 1950's also corresponds to a particular choice within the similarity renormalization framework, and it is argued that Dyson's scheme is preferable to the others for ease of computation. As an example, it is shown how a logarithmically confining potential arises simply at second order in light-front QCD within Dyson's scheme, a result found previously for other similarity renormalization schemes. Steps toward higher order and nonperturbative calculations are outlined. In particular, a set of equations analogous to Dyson-Schwinger equations is developed.Comment: REVTex, 32 pages, 7 figures (corrected references

Anderson transitions in three-dimensional disordered systems with randomly varying magnetic flux

The Anderson transition in three dimensions in a randomly varying magnetic flux is investigated in detail by means of the transfer matrix method with high accuracy. Both, systems with and without an additional random scalar potential are considered. We find a critical exponent of $\nu=1.45\pm0.09$ with random scalar potential. Without it, $\nu$ is smaller but increases with the system size and extrapolates within the error bars to a value close to the above. The present results support the conventional classification of universality classes due to symmetry.Comment: 4 pages, 2 figures, to appear in Phys. Rev.