Quantum photon emission from a moving mirror in the nonperturbative regime

We consider the coupling of the electromagnetic vacuum field with an oscillating perfectly-reflecting mirror in the nonrelativistic approximation. As a consequence of the frequency modulation associated to the motion of the mirror, low frequency photons are generated. We calculate the photon emission rate by following a nonperturbative approach, in which the coupling between the field sidebands is taken into account. We show that the usual perturbation theory fails to account correctly for the contribution of TM-polarized vacuum fluctuations that propagate along directions nearly parallel to the plane surface of the mirror. As a result of the modification of the field eigenfunctions, the resonance frequency for photon emission is shifted from its unperturbed value.Comment: 11 pages, 3 figures. To be published in Optics Communication

Roughness correction to the Casimir force : Beyond the Proximity Force Approximation

We calculate the roughness correction to the Casimir effect in the parallel plates geometry for metallic plates described by the plasma model. The calculation is perturbative in the roughness amplitude with arbitrary values for the plasma wavelength, the plate separation and the roughness correlation length. The correction is found to be always larger than the result obtained in the Proximity Force Approximation.Comment: 7 pages, 3 figures, v2 with minor change

Particle Creation by a Moving Boundary with Robin Boundary Condition

We consider a massless scalar field in 1+1 dimensions satisfying a Robin boundary condition (BC) at a non-relativistic moving boundary. We derive a Bogoliubov transformation between input and output bosonic field operators, which allows us to calculate the spectral distribution of created particles. The cases of Dirichlet and Neumann BC may be obtained from our result as limiting cases. These two limits yield the same spectrum, which turns out to be an upper bound for the spectra derived for Robin BC. We show that the particle emission effect can be considerably reduced (with respect to the Dirichlet/Neumann case) by selecting a particular value for the oscillation frequency of the boundary position

Dynamical Casimir effect with cylindrical waveguides

I consider the quantum electromagnetic field in a coaxial cylindrical waveguide, such that the outer cylindrical surface has a time-dependent radius. The field propagates parallel to the axis, inside the annular region between the two cylindrical surfaces. When the mechanical frequency and the thickness of the annular region are small enough, only Transverse Electromagnetic (TEM) photons may be generated by the dynamical Casimir effect. The photon emission rate is calculated in this regime, and compared with the case of parallel plates in the limit of very short distances between the two cylindrical surfaces. The proximity force approximation holds for the transition matrix elements in this limit, but the emission rate scales quadratically with the mechanical frequency, as opposed to the cubic dependence for parallel plates.Comment: 6 page

An alternative theoretical approach to describe planetary systems through a Schrodinger-type diffusion equation

In the present work we show that planetary mean distances can be calculated with the help of a Schrodinger-type diffusion equation. The obtained results are shown to agree with the observed orbits of all the planets and of the asteroid belt in the solar system, with only three empty states. Furthermore, the equation solutions predict a fundamental orbit at 0.05 AU from solar-type stars, a result confirmed by recent discoveries. In contrast to other similar approaches previously presented in the literature, we take into account the flatness of the solar system, by considering the flat solutions of the Schrodinger-type equation. The model has just one input parameter, given by the mean distance of Mercury.Comment: 6 pages. Version accepted for publication in Chaos, Solitons & Fractal

The Casimir force between rough metallic plates

The Casimir force between two metallic plates is affected by their roughness state. This effect is usually calculated through the so-called `proximity force approximation' which is only valid for small enough wavevectors in the spectrum of the roughness profile. We introduce here a more general description with a wavevector-dependent roughness sensitivity of the Casimir effect. Since the proximity force approximation underestimates the effect, a measurement of the roughness spectrum is needed to achieve the desired level of accuracy in the theory-experiment comparison.Comment: 7 pages, 1 figure, epl style, minor change

Huet sceptique cartésien

Pierre-Daniel Huet est un des sceptiques les plus importants de la fin du XVIIe siècle et du début du XVIIIe siècle. Dans cet article, je cherche à montrer en six points que la principale source du scepticisme de Huet est paradoxalement Descartes, chaque point étant développé dans une section du texte : 1) Huet a découvert le doute cartésien avant de connaître le doute sceptique des anciens ; 2) le scepticisme du Traité Philosophique de la Faiblesse de l’Esprit Humain et l’anti-cartésianisme de la Censura Philosophiae Cartesianae faisaient originellement partie d’une même ouvrage ; 3) on trouve un Descartes sceptique dans la Censura ; 4) la biographie intellectuelle du Provençal dans le Traité Philosophique actualise et pyrrhonise la biographie intellectuelle du Descartes du Discours de la Méthode ; 5) quatre arguments sceptiques du Traité, dont le plus important de l’ouvrage, sont cartésiens ; 6) le scepticisme de Huet a été perçu par les premiers lecteurs du manuscrit du Traité comme partialement cartésien.Pierre-Daniel Huet is one of the most important skeptics from the end of the 17th/begining of the 18th centuries. In this article, I show that Descartes is the main source of Huet’s skepticism by means of six remarks, each developed in a section of the article. 1) Huet discovered Cartesian doubt before he discovered ancient skeptical doubt ; 2) the skepticism exhibited in the Traité Philosophique de la Faiblesse de l’Esprit Humain and the anti-cartesianism exhibited in the Censura Philosophiae Cartesianae were originally parts of the same work ; 3) there is a skeptical Descartes in the Censura ; 4) the intellectual biography of the Provençal in the Traité Philosophique updates and pyrrhonizes Descartes’s intellectual biography in the Discours de la Méthode ; 5) four skeptical arguments in the Traité — including the most important one in the book — are Cartesian ; 6) Huet’s skepticism was perceived as partially Cartesian by the first readers of the manuscript