44 research outputs found

    Entropy function from the Einstein boundary term

    Full text link
    We show using the entropy function formalism developed by Sen \cite{Sen:2005wa} that the boundary term which arises from the Einstein-Hilbert action is sufficient to yield the Bekenstein-Hawking entropy of a static extremal black hole which is asymptotically flat. However, for asymptotically AdSAdS black holes, the bulk term also plays an important role due to the presence of the cosmological constant. Further, we show that for extremal rotating black holes, both the boundary and the bulk terms contribute non-vanishing pieces to the entropy.Comment: v1: 9 pages LaTex, v2: 10 pages LaTex (to appear in Europhysics Letters

    The role of mutual information in the Page curve

    Full text link
    In this work, we give two proposals regarding the status of connectivity of entanglement wedges and the associated saturation of mutual information. The first proposal has been given for the scenario before the Page time depicting the fact that at a particular value of the observer's time tb=tRt_b=t_R (where tRβt_R\ll\beta), the mutual information I(R+:R)I(R_+:R_-) vanishes representing the disconnected phase of the radiation entanglement wedge. We argue that this time is the Hartman-Maldacena time at which the fine-grained entropy of radiation goes as S(R)log(β)S(R)\sim \log(\beta), where β\beta is the inverse of Hawking temperature of the black hole. On the other hand, the second proposal probes the crucial role played by the mutual information of black hole subsystems in obtaining the correct Page curve of radiation.Comment: v1: 7 pages LaTex, 2 figures, v2: 9 pages LaTex, 2 figures. Accepted for publication in Physical Review

    Mutual information of subsystems and the Page curve for Schwarzschild de-Sitter black hole

    Full text link
    In this work, we show that the two proposals associated to the mutual information of matter fields can be given for an eternal Schwarzschild black hole in de-Sitter spacetime. These proposals also depicts the status of associated entanglement wedges and their roleplay in obtaining the correct Page curve of radiation. The first proposal has been give for the before Page time scenario, which shows that the mutual information I(RH+:RH)I(R_{H}^{+}:R_{H}^{-}) vanishes at a certain value of the observer's time tbH=tHt_{b_{H}}=t_{H} (where tHβHt_{H}\ll \beta_{H}). We claim that this is the Hartman-Maldacena time at which the entanglement wedge associated to RH+RHR_{H}^{+}\cup R_{H}^{-} gets disconnected and the fine-grained radiation entropy has the form S(RH)log(βH)S(R_{H})\sim \log(\beta_{H}). The second proposal depicts the fact that just after the Page time, when the replica wormholes are the dominating saddle-points, the mutual information I(BH+:BH)I(B_{H}^{+}:B_{H}^{-}) vanishes as soon as the time difference taHtbHt_{a_{H}}-t_{b_{H}} equals the scrambling time. Holographically, this reflects that the entanglement wedge associated to BH+BHB_{H}^{+}\cup B_{H}^{-} jumps to the disconnected phase at this particular time-scale. Furthermore, these two proposals lead us to the correct time-evolution of the fine-grained entropy of radiation as portrayed by the Page curve. We have also shown that similar observations can be obtained for the radiation associated to the cosmological horizon.Comment: v1:18 pages LaTex with multiple figures, v2: matches with the accepted version; To appear in Physical Review

    Mixed state information theoretic measures in boosted black brane

    Full text link
    In this paper, we study various mixed state information theoretic quantities for a boosted black brane geometry. We have considered two set ups, namely, the subsystem taken parallel and perpendicular to the direction of the boost. The quantities that we calculate are the entanglement wedge cross-section, mutual information, entanglement negativity and mutual complexity. In particular, we study the dependence of these quantities on the boost parameter. We then proceed to calculate the asymmetry ratios of these quantities, and observe that they are independent of the subsystem size. Finally, we proceed to study an interesting limit of the boosted black brane geometry, which is the so called AdS wave geometry. We once again compute all the mixed state information theoretic quantities for this geometry.Comment: 32 pages LaTex and 9 figures, comments are welcom

    Evaluation of an organic package of practice towards integrated management of Solanum tuberosum and its comparison with conventional farming in terms of yield, quality, energy efficiency and economics

    Get PDF
    A study was taken up during 2014-16 for evaluating the potential of an organic package of practice towards integrated crop production (green farming) in comparison to conventional farmers’ practice in West Bengal, India. Under green farming, compost was integrated with chemical fertilizer for soil management while organic plant/ pest management was undertaken utilizing Inhana Rational Farming (IRF) Technology. The study indicated higher yield (9.7 %), higher nutrient use efficiency and economic sustainability under green farming irrespective of study area or potato variety. Higher qualitative expression in terms of starch content, pulp pH, vitamin C etc. under green farming might be due to the organic plant management aimed at energization of plant biochemical functions. Soil quality development as noted under green farming might have been influenced by the on-farm produced compost containing rich self- generated micro flora (in order of 1016 per colony forming unit.). The study indicated that green farming may serve as an efficient substitute of conventional farming towards yield sustenance, abatement of food toxicity and quality end product; through higher use of renewable energy and activation of plant physiological functions

    Evaluation of Different Organic ‘Packages of Practice’ in Young Tea Plantation: A case study under FAO-CFC-TBI Project at Maud Tea Estate, Assam, India

    Get PDF
    Maintenance of young tea under organic package of practice is a challenging task and needs a proper intervention. The present study under FAO-CFC-TBI project was done at Maud Tea Estate, Assam, India to find out an effective pathway for growing healthy and productive young tea plants. Seven different organic packages of practice were chosen to evaluate their potential in terms of crop efficiency as well as soil quality rejuvenation. Crop yield was recorded of highest value under Inhana Rational Farming (IRF-2: made tea 807 kgha-1) package of practice. Yield under the treatment was 55.2 percent higher than control and about 25.6 percent higher than the next best performing package of practice i.e. VMI (653 kgha-1). The third highest yield was obtained under IRF-1 and VCO, which recorded almost similar crop (made tea: 619 & 618 kgha-1 resp.) followed by BD (593 kgha-1), Co (567 kgha-1) and MI (556 kgha-1) packages. Value cost ratio (VCR), which is excess revenue generated per unit rupee invested; followed similar trend as observed in case of New Plantation experiment indicating highest economic sustainability under IRF-2 (4.37) followed by IRF-1 (2.33) package. Value cost ratio in case of other organic packages varied between 0.25 and 1.02, indicating economic vulnerability considering that VCR < 2.00 has been indicated by Agricultural economists as the critical mark below which there is no necessary risk coverage against investment towards input cost

    Activation of decapping involves binding of the mRNA and facilitation of the post-binding steps by the Lsm1-7–Pat1 complex

    No full text
    Decapping is a critical step in the conserved 5′-to-3′ mRNA decay pathway of eukaryotes. The hetero-octameric Lsm1-7–Pat1 complex is required for normal rates of decapping in this pathway. This complex also protects the mRNA 3′-ends from trimming in vivo. To elucidate the mechanism of decapping, we analyzed multiple lsm1 mutants, lsm1-6, lsm1-8, lsm1-9, and lsm1-14, all of which are defective in decapping and 3′-end protection but unaffected in Lsm1-7–Pat1 complex integrity. The RNA binding ability of the mutant complex was found to be almost completely lost in the lsm1-8 mutant but only partially impaired in the other mutants. Importantly, overproduction of the Lsm1-9p- or Lsm1-14p-containing (but not Lsm1-8p-containing) mutant complexes in wild-type cells led to a dominant inhibition of mRNA decay. Further, the mRNA 3′-end protection defect of lsm1-9 and lsm1-14 cells, but not the lsm1-8 cells, could be partly suppressed by overproduction of the corresponding mutant complexes in those cells. These results suggest the following: (1) Decapping requires both binding of the Lsm1-7–Pat1 complex to the mRNA and facilitation of the post-binding events, while binding per se is sufficient for 3′-end protection. (2) A major block exists at the post-binding steps in the lsm1-9 and lsm1-14 mutants and at the binding step in the lsm1-8 mutant. Consistent with these ideas, the lsm1-9, 14 allele generated by combining the mutations of lsm1-9 and lsm1-14 alleles had almost fully lost the RNA binding activity of the complex and behaved like the lsm1-8 mutant
    corecore