Black-hole quasinormal modes and scalar glueballs in a finite-temperature AdS/QCD model

We use the holographic AdS/QCD soft-wall model to investigate the spectrum of scalar glueballs in a finite temperature plasma. In this model, glueballs are described by a massless scalar field in an AdS_5 black hole with a dilaton soft-wall background. Using AdS/CFT prescriptions, we compute the boundary retarded Green's function. The corresponding thermal spectral function shows quasiparticle peaks at low temperatures. We also compute the quasinormal modes of the scalar field in the soft-wall black hole geometry. The temperature and momentum dependences of these modes are analyzed. The positions and widths of the peaks of the spectral function are related to the frequencies of the quasinormal modes. Our numerical results are found employing the power series method and the computation of Breit-Wigner resonances.Comment: Revision: Results unchanged. More discussions on the model and on the results. References added. 28 pages, 7 figures, 5 table

Distributed phase-covariant cloning with atomic ensembles via quantum Zeno dynamics

We propose an interesting scheme for distributed orbital state quantum cloning with atomic ensembles based on the quantum Zeno dynamics. These atomic ensembles which consist of identical three-level atoms are trapped in distant cavities connected by a single-mode integrated optical star coupler. These qubits can be manipulated through appropriate modulation of the coupling constants between atomic ensemble and classical field, and the cavity decay can be largely suppressed as the number of atoms in the ensemble qubits increases. The fidelity of each cloned qubit can be obtained with analytic result. The present scheme provides a new way to construct the quantum communication network.Comment: 5 pages, 4 figure

Morphology and foliar chemistry of containerized Abies fraseri (Pursh) Poir. seedlings as affected by water availability and nutrition

• We present the results of a two-year (2007–2008) greenhouse study investigating the effect of water availability and nitrogen fertilization on the growth, biomass partitioning, and foliar nutrient content of Abies fraseri (Pursh) Poir. • Fertilizer and moisture content (irrigation) were varied in a factorial experiment combining four levels of irrigation and three levels of fertilization to evaluate growth and foliar nutrient content. In addition, a numerical optimization was used to estimate appropriate levels of each factor necessary to achieve simulated goals for response variables. • Irrigation increased the height growth by 12 to 35% depending on the fertilization treatment (p = 0.0001). Fertilization increased height growth by 10 to 26% (p = 0.02). A similar response was observed for stem diameter growth (SDG). Total biomass accumulation increased as result of positive response of stem and root biomass development, and foliar nitrogen content was positively affected by nitrogen fertilization and negatively affected by irrigation. The numerical optimization for simulated target growth and nitrogen content responses produced levels of input combinations with high desirability factors to achieve the target responses. • These results suggest that nutrient addition is a strong determining factor for early development of this species. The improved growth efficiency in this study is likely attributed to a combination of factors including, improved photosynthetic capacity, decreased stomatal limitations, or increased resource allocation to stems

Toward an internally consistent astronomical distance scale

Accurate astronomical distance determination is crucial for all fields in astrophysics, from Galactic to cosmological scales. Despite, or perhaps because of, significant efforts to determine accurate distances, using a wide range of methods, tracers, and techniques, an internally consistent astronomical distance framework has not yet been established. We review current efforts to homogenize the Local Group's distance framework, with particular emphasis on the potential of RR Lyrae stars as distance indicators, and attempt to extend this in an internally consistent manner to cosmological distances. Calibration based on Type Ia supernovae and distance determinations based on gravitational lensing represent particularly promising approaches. We provide a positive outlook to improvements to the status quo expected from future surveys, missions, and facilities. Astronomical distance determination has clearly reached maturity and near-consistency.Comment: Review article, 59 pages (4 figures); Space Science Reviews, in press (chapter 8 of a special collection resulting from the May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space Age