Search results for "quantum electrodynamics"

Maximum Principle and Application to Nuclear Magnetic Resonance and Magnetic Resonance Imaging

2018

In this section we state the Pontryagin maximum principle and we outline the proof. We adopt the presentation from Lee and Markus [64] where the result is presented into two theorems.

A Coherent Master Equation for active mode locking in lasers

2015

We present the derivation of a new master equation for active mode locking in lasers that fully takes into account the coherent effects of the light matter interaction through a peculiar adiabatic elimination technique. The coherent effects included in our model could be relevant to describe properly mode-locked semiconductor lasers where the standard Haus’ Master Equation predictions show some discrepancy with respect to the experimental results and can be included in the modelling of other mode locking techniques too.

QQ-onia package: a numerical solution to the Schrodinger radial equation for heavy quarkonium

2008

30 pages, 3 figures.-- ISI article identifier:000265158700009.-- ArXiv pre-print avaible at: http://arxiv.org/abs/0805.2704

Quantum Stochastic Resonance in a Micromaser

1998

We demonstrate that quantum stochastic resonance allows for the noise-controlled synchronization of quantum jumps between the metastable states of the quantized radiation field in a micromaser. Under readily accessible experimental conditions optimal synchronization is achieved at a finite temperature $T\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}500\mathrm{mK}$ of the environment.

On the momentum dependence ofJ/? suppression

1988

The formation of deconfined matter in high energy collisions is expected to result in reducedJ/ψ production. The finite space-time extension of any quark-gluon plasma thus produced leads to a rather characteristic dependence ofJ/ψ suppression on the longitudinal and transverse momentum of theJ/ψ. We study in particular the longitudinal momentum dependence and discuss its implications for nuclear collision experiments.

Study of the anomalous magnetic moment of the muon computed from the Adler function

2014

We compute the Adler function on the lattice from vacuum polarization data with twisted boundary conditions using numerical derivatives. The study is based on CLS ensembles with two flavours of $O(a)$ improved Wilson fermions. We extrapolate the lattice data for the Adler function to the continuum limit and to the physical pion mass and analyze its dependence on the momentum transfer. We discuss the application of this method to the extraction of the $u,d$ contribution to $a_\mu^{\mathrm{HLO}}$.

Nonequilibrium statistical mechanics of dilute relativistic plasmas

2005

Theory of quantum fluctuations of optical dissipative structures - Application to the study of squeezing and intensity fluctuations of DOPO cavity so…

2007

We present a general theory of quantum fluctuations of dissipative structures in nonlinear optical cavities with transverse translation invariance. Perfect squeezing of the transverse momentum, detectable under homodyning, occurs irrespectively of the system parameters.

Oscillations of a highly discrete breather with a critical regime

2000

We analyze carefully the essential features of the dynamics of a stationary discrete breather in the ultimate degree of energy localization in a nonlinear Klein-Gordon lattice with an on-site double-well potential. We demonstrate the existence of three different regimes of oscillatory motion in the breather dynamics, which are closely related to the motion of the central particle in an effective potential having two nondegenerate wells. In given parameter regions, we observe an untrapped regime, in which the central particle executes large-amplitude oscillations from one to the other side of the potential barrier. In other parameter regions, we find the trapped regime, in which the central …

Nonlinear SDE Excited by External Lévy White Noise Processes

2011

A numerical method for approximating the statistics of the solution of nonlinear stochastic systems excited by Gaussian and non-Gaussian external white noises is proposed. The differential equation governing the evolution in time of the characteristic function is resolved by the convolution quadrature method. This approach is especially suited for those problems in which the nonlinear drift term is not of polynomial form. In such cases the equation governing the evolution in time of the characteristic function is not a partial differential equation. Statistics are found by introducing an integral operator of Wiener-Hopf type, called the transformation operator, and applying the Lubich's con…