Quantum transport with coupled cavities on the Apollonian network

We study the dynamics of single photonic and atomic excitations in the Jaynes-Cummings-Hubbard (JCH) model where the cavities are arranged in an Apollonian network (AN). The existence of a gapped field normal frequency spectrum along with strongly localized eigenstates on the AN highlights many of the features provided by the model. By numerically diagonalizing the JCH Hamiltonian in the single excitation subspace, we evaluate the time evolution of fully localized initial states, for many energy regimes. We provide a detailed description of the photonic quantum walk on the AN and also address how an effective Jaynes-Cummings interaction can be achieved at the strong hopping regime. When the hopping rate and the atom-field coupling strength is of the same order, the excitation is relatively allowed to roam between atomic and photonic degrees of freedom as it propagates. However, different cavities will contribute mostly to one of these components, depending on the detuning and initial conditions, in contrast to the strong atom-field coupling regime, where atomic and photonic modes propagate identically.Comment: 10 pages, 10 figure

A Generalization of a Gaussian Semiparametric Estimator on Multivariate Long-Range Dependent Processes

In this paper we propose and study a general class of Gaussian Semiparametric Estimators (GSE) of the fractional differencing parameter in the context of long-range dependent multivariate time series. We establish large sample properties of the estimator without assuming Gaussianity. The class of models considered here satisfies simple conditions on the spectral density function, restricted to a small neighborhood of the zero frequency and includes important class of VARFIMA processes. We also present a simulation study to assess the finite sample properties of the proposed estimator based on a smoothed version of the GSE which supports its competitiveness

Rapidity dependence of particle densities in pp and AA collisions

We use multiple scattering and energy conservation arguments to describe $dn/d\eta_{NANA}$ as a function of $dn/d\eta_{pp}$ in the framework of string percolation. We discuss the pseudo-rapidity $\eta$? and beam rapidity Y dependence of particle densities. We present our results for pp, Au- Au, and Pb-Pb collisions at RHIC and LHC.Comment: 12 pages, 6 figure