Search results for "current"

Poincaré's role in the Crémieu-Pender controversy over electric convection

1989

Summary In the course of 1901, V. Cremieu published the results of some experiments carried out to test the magnetic effects of electric convection currents. According to Cremieu, his experiments had proved that convection currents had no magnetic effects and consequently they were not equivalent to conduction currents, that is they were not ‘real’ electric currents. These negative results conflicted with those of well-known experiments carried out by other researchers, in particular with Rowland's experiments, and with Maxwell's, Hertz's and Lorentz's theories, which was more shocking. The publication of Cremieu's experiments raised a controversy which involved directly or indirectly some …

More about a successful vector-tensor theory of gravitation

2016

The vector-tensor (VT) theory of gravitation revisited in this article was studied in previous papers, where it was proved that VT works and deserves attention. New observational data and numerical codes have motivated further development which is presented here. New research has been planed with the essential aim of proving that current cosmological observations, including Planck data, baryon acoustic oscillations (BAO), and so on, may be explained with VT, a theory which accounts for a kind of dark energy which has the same equation of state as vacuum. New versions of the codes CAMB and COSMOMC have been designed for applications to VT, and the resulting versions have been used to get the…

Canonical Neutral Current Predictions From The Weak Electromagnetic Gauge Group SU(3) X U(1)

1980

A straightforward SU(3) x U(1) model in which there is effectively one new neutral-current parameter (denoted by R) is shown to give the canonical neutrino neutral-current predictions for all values of R. For small R the ''low-energy'' theory is essentially SU(2) x U(1) while for R of the order of one it has a much richer ''low-energy'' gauge-boson mass spectrum. Even in the latter case, the predicted e-d asymmetry agrees with experiment. It is interesting that the atomic-physics parity violation depends sensitively on R.

Vector screening masses in the quark–gluon plasma and their physical significance

2014

Static and non-static thermal screening states that couple to the conserved vector current are investigated in the high-temperature phase of QCD. Their masses and couplings to the current are determined at weak coupling, as well as using two-flavor lattice QCD simulations. A consistent picture emerges from the comparison, providing evidence that non-static Matsubara modes can indeed be treated perturbatively. We elaborate on the physical significance of the screening masses.

The Fock Bundle of a Dirac Operator and Infinite Grassmannians

1989

In the earlier chapters we have studied representations of current algebras in fermionic Fock spaces. A (fermionic) Fock space is determined by a single Dirac operator D. To set up a Fock space we need a splitting of a complex Hilbert space H to the subspaces H± corresponding to positive and negative frequencies of D. However, in an interacting quantum field theory one really should consider a bundle of Fock spaces parametrized by different Dirac operators. For example, in Yang-Mills theory any smooth vector potential defines a Dirac operator and one must consider the whole bunch of these operators and associated Fock spaces if one wants to describe the interaction of the vector potential w…

A coupled-map model for the magnetotail current sheet

1999

A magnetic field model of the magnetotail current sheet in the form of a coupled-map lattice (CML) is presented. It is a continuously driven and based on the MHD diffusion equation. Solar wind vBs data (solar wind speed multiplied by the southward component of IMF) are used for driving the model, and it is shown to exhibit perturbations (avalanches) with power-law scalings in their distributions of duration and size. Such distributions may indicate self-organized critical (SOC) behavior. Furthermore, it is shown that the power spectra of the model outputs are of bicolor power-law form with different slopes for high and low frequencies. The model parameters determine the frequency of the bre…

Electric field driven domain wall transfer in hybrid structures

2012

Domain wall (DW) motion devices attracts much interest with their prospective logic and memory applications[1][2]. Present on-chip DW manipulations by a magnetic field of electric currents or electron spin torque raise the problem of high Ohmic energy losses. We show that such a difficulty can be avoided by applying an exchange field H eff to the magnetic layer from the proximate graphene (Gr), instead of using an actual magnetic field. H eff is shown to be dependent on carrier density gradient in Gr, which is easily manipulated with a gate voltage. A novel memory device implementing this concept is designed and modeled, demonstrating switching power well below femto-Joule while maintaining…

Chemical studies of elements with Z≥ 104 in liquid phase

2015

Abstract Recent studies of the chemical separation and characterization experiments of the first three transactinide elements, rutherfordium (Rf), dubnium (Db), and seaborgium (Sg), conducted atom-at-a-time in liquid phases, are reviewed. A short description on experimental techniques based on partition methods, specifically automated rapid chemical separation systems, is also given. A newly developed experimental approach to investigate single atoms of the heaviest elements with an electrochemical method is introduced. Perspectives for liquid-phase chemistry experiments on heavier elements are briefly discussed.

Neutral-current effects in elastic electron-nucleon scattering

1974

The coherent weak charge of matter

2017

We study the long-range force arising between two aggregates of ordinary matter due to a neutrino-pair exchange, in the limit of zero neutrino mass. Even if matter is neutral of electric charge, it is charged for this weak force. The interaction is described in terms of a coherent charge, which we call the weak flavor charge of aggregated matter. For each one of the interacting aggregates, this charge depends on the neutrino flavor as $Q_W^{\nu_e} = 2Z-N$, $Q_W^{\nu_\mu} = Q_W^{\nu_\tau} = -N$, where $Z$ is the number of protons and $N$ the number of neutrons. $Q_W^{\nu_e}$ depends explicitly on $Z$ because of the charged current contribution to $\nu_e e$ elastic scattering, while the $N$ t…