16,802 research outputs found

    Neutrinos in the holographic dark energy model: constraints from latest measurements of expansion history and growth of structure

    Full text link
    The model of holographic dark energy (HDE) with massive neutrinos and/or dark radiation is investigated in detail. The background and perturbation evolutions in the HDE model are calculated. We employ the PPF approach to overcome the gravity instability difficulty (perturbation divergence of dark energy) led by the equation-of-state parameter ww evolving across the phantom divide w=βˆ’1w=-1 in the HDE model with c<1c<1. We thus derive the evolutions of density perturbations of various components and metric fluctuations in the HDE model. The impacts of massive neutrino and dark radiation on the CMB anisotropy power spectrum and the matter power spectrum in the HDE scenario are discussed. Furthermore, we constrain the models of HDE with massive neutrinos and/or dark radiation by using the latest measurements of expansion history and growth of structure, including the Planck CMB temperature data, the baryon acoustic oscillation data, the JLA supernova data, the Hubble constant direct measurement, the cosmic shear data of weak lensing, the Planck CMB lensing data, and the redshift space distortions data. We find that βˆ‘mΞ½<0.186\sum m_\nu<0.186 eV (95\% CL) and Neff=3.75βˆ’0.32+0.28N_{\rm eff}=3.75^{+0.28}_{-0.32} in the HDE model from the constraints of these data.Comment: 18 pages, 5 figures; revised version accepted for publication in JCA

    Faithful teleportation with arbitrary pure or mixed resource states

    Full text link
    We study faithful teleportation systematically with arbitrary entangled states as resources. The necessary conditions of mixed states to complete perfect teleportation are proved. Based on these results, the necessary and sufficient conditions of faithful teleportation of an unknown state |\phi> in C^d with an entangled resource {\rho} in C^m \otimes C^d and C^d \otimes C^n are derived. It is shown that for {\rho} in C^m\otimesC^d, {\rho} must be a maximally entangled state, while for {\rho} in C^d \otimes C^n, {\rho} must be a puremaximally entangled state. Moreover, we show that the sender's measurements must be all projectors of maximally entangled pure states. The relations between the entanglement of the formation of the resource states and faithful teleportation are also discussed.Comment: 9 page
    • …
    corecore