Concept

Four-vector

Related publications (97)

Antenna excitation of drift wave in a toroidal plasma

Ambrogio Fasoli, Ivo Furno, Paolo Ricci, Benoît Labit, Mario Ludovico Podesta, Francesca Maria Poli, Stefan Müller

In a magnetized toroidal plasma, an antenna tunable in vertical wave number is used to excite density perturbations. Coherent detection is performed by means of Langmuir probes to directly determine both the wave vector and the plasma response induced by t ...

American Institute of Physics2007

Incommensurate magnetic ordering in Cu2Te2O5X2 (X=Cl,Br) studied by single crystal neutron diffraction

Henrik Moodysson Rønnow, Helmuth Berger, Joël Mesot

Polarized and unpolarized neutron-diffraction studies have been carried out on single crystals of the coupled spin tetrahedra systems Cu2Te2O5X2 (X=Cl, Br). A model of the magnetic structure associated with the propagation vectors k(') (Cl) approximate to ...

2006

Relativistic Hamiltonian guiding center drift formalism in anisotropic pressure magnetic coordinates

Jonathan Graves, Wilfred Anthony Cooper, Martin Jucker

A Hamiltonian formulation of the relativistic guiding center drifts is extended to anisotropic pressure plasmas. The magnetic coordinates devised by Boozer are adapted to the anisotropic pressure model and retain canonical properties for two-dimensional an ...

2006

Multi target direction-of-arrival tracking using road priors

Volkan Cevher

In this paper, we present a multi target particle filter DOA tracker that can incorporate road prior information at a single array node. The filter uses a batch of DON's to determine the state vector, based on an image template matching idea. The filter li ...

2006

Automatic procedure for aberration compensation in digital holographic microscopy and applications to specimen shape compensation

Christian Depeursinge, Tristan Colomb, Etienne Cuche, Frédéric Montfort, Nicolas Aspert, Pierre Marquet, Jonas Kühn, Florian Charrière

We present a procedure that compensates for phase aberrations in digital holographic microscopy by computing a polynomial phase mask directly from the hologram. The phase-mask parameters are computed automatically without knowledge of physical values such ...

2006

Velocity Scheduling Controller for a Nonholonomic Mobile Robot

Dominique Bonvin, Philippe Müllhaupt, Davide Buccieri

An improvement over classical dynamic feedback linearization for the control of a nonholonomic mobile robot is proposed. The use of a state extension of higher dimension than in the case of dynamic feedback linearization helps reject constant disturbances ...

2006

Modelling the effect of particle size, shape and orientation of light transfer through porous media

In this study, we present a radiative-transfer model to simulate reflectance and transmittance of light by soil slabs. The radiative-transfer model implemented, referred to as the beam-tracing model, uses cross-sectional images of scattering media to descr ...

2005

Resolving the wave vector in negative refractive index media

Olivier Martin

We address the general issue of resolving the wave vector in complex electromagnetic media including negative refractive media. This requires us to make a physical choice of the sign of a square root imposed merely by conditions of causality. By considerin ...

Optical Society of America2005

One-loop fermionic corrections to the instanton transition in two dimensional chiral Higgs model

Yannis Burnier

The one-loop fermionic contribution to the probability of an instanton transition with fermion number violation is calculated in the chiral Abelian Higgs model in 1+1 dimensions, where the fermions have a Yukawa coupling to the scalar field. The dependence ...

2005

Evidence for the decay ∑+ → pμ+ μ-

Yixing Chen, Yu Fu

We report the first evidence for the decay ∑+ → pμ+ μ- from data taken by the HyperCP (E871) experiment at Fermilab. Based on three observed events, the branching ratio is B(∑+ → pμ+ μ-) = [8.6 -5.4 +6.6(stat) ± 5.5(syst)] × 10 -8. The narrow range of dimu ...

2005

Graph Chatbot

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.