Anomalous effective action, Noether current, Virasoro algebra and Horizon entropy

Several investigations show that in a very small length scale there exists corrections to the entropy of black hole horizon. Due to fluctuations of the background metric and the external fields the action incorporates corrections. In the low energy regime, the one loop effective action in four dimensions leads to trace anomaly. We start from the Noether current corresponding to the Einstein-Hilbert plus the one loop effective action to calculate the charge for the diffeomorphisms which preserve the Killing horizon structure. Then a bracket among the charges is calculated. We show that the Fourier modes of the bracket is exactly similar to Virasoro algebra. Then using Cardy formula the entropy is evaluated. Finally, the explicit terms of the entropy expression is calculated for a classical background. It turns out that the usual expression for entropy; i.e. the Bekenstein-Hawking form, is not modified.Comment: Minor modifications, to appear in EPJ

Structural and Optical Studies on Sol-gel Composites of Nickel-Doped Nanocrystalline Zinc Oxide/Polyvinylidene Fluoride

Nickel-doped nanocrystalline ZnO with three different Ni concentrations was incorporated in polyvinylidene fluoride thin film for obtaining free-standing flexible film by sol-gel technique. The effect of Ni-ZnO loading on the optical and microstructural properties of the Ni-ZnO/polyvinylidene fluoride composite films was studied. X-ray photoelectron spectroscopy and Raman studies were performed to characterize the bonding environment. Fluorine-terminated surface showed a strong F1 s peak located at similar to 695 eV arising out of C-F bonds. Existence of. phase of polyvinylidene fluoride along with the presence of ZnO nanocrystals were indicated by Raman studies. Secondary ion mass spectrometry studies indicated the distribution of Ni-ZnO particles in the polyvinylidene fluoride matrix

Structural and Optical Studies on Sol-gel Composites of Nickel-Doped Nanocrystalline Zinc Oxide/Polyvinylidene Fluoride

Nickel-doped nanocrystalline ZnO with three different Ni concentrations was incorporated in polyvinylidene fluoride thin film for obtaining free-standing flexible film by sol-gel technique. The effect of Ni-ZnO loading on the optical and microstructural properties of the Ni-ZnO/polyvinylidene fluoride composite films was studied. X-ray photoelectron spectroscopy and Raman studies were performed to characterize the bonding environment. Fluorine-terminated surface showed a strong F1 s peak located at similar to 695 eV arising out of C-F bonds. Existence of. phase of polyvinylidene fluoride along with the presence of ZnO nanocrystals were indicated by Raman studies. Secondary ion mass spectrometry studies indicated the distribution of Ni-ZnO particles in the polyvinylidene fluoride matrix