11,416 research outputs found

    Lovelock type gravity and small black holes in heterotic string theory

    Full text link
    We analyze near horizon behavior of small D-dimensional 2-charge black holes by modifying tree level effective action of heterotic string with all extended Gauss-Bonnet densities. We show that there is a nontrivial and unique choice of parameters, independent of D, for which the black hole entropy in any dimension is given by 4\pi\sqrt{nw}, which is exactly the statistical entropy of 1/2-BPS states of heterotic string compactified on T^{9-D}\times S^1 with momentum n and winding w. This extends the results of Sen [JHEP 0507 (2005) 073] to all dimensions. We also show that our Lovelock type action belongs to the more general class of actions sharing the simmilar behaviour on the AdS_2\times S^{D-2} near horizon geometry.Comment: 14 pages, JHEP styl

    Search for flavor-changing interactions of the top quark with the Higgs boson in HbbˉH \rightarrow b \bar{b} channel at s=13TeV\sqrt{s}\,=\,13\,\mathrm{TeV}

    Full text link
    A search for flavor-changing neutral current (FCNC) processes in associated production of a top quark and Higgs boson, with the Higgs boson decaying to a pair of b quarks, is presented. To experimentally probe the top-Higgs FCNC couplings, for the first time the single-top production is considered as a signal process. One isolated lepton and at least three reconstructed jets, among which at least two are identified as b quark jets, are found in the final state. The data sample corresponds to an integrated luminosity of 35.9fb135.9\,\mathrm{fb^{-1}} recorded by the CMS experiment at the LHC in proton-proton collisions at s=13TeV\sqrt{s}\,=\,13\,\mathrm{TeV} in 2016, and the final results are presented in the form of the observed and expected 95\% CL upper limits on the branching ratio of top quark decays

    Anthropocene, Capitalocene, Machinocene: Illusions of instrumental reason

    Get PDF
    In their seminal work, Dialectics of Enlightenment, Horkheimer and Adorno interpreted capitalism as the irrational monetization of nature. In the present work, I analyze three 21st century concepts, Anthropocene, Capitalocene and Machinocene, in light of Horkheimer and Adorno’s arguments and recent arguments from the philosophy of biology. The analysis reveals a remarkable prescience of the term “instrumental reason”, which is present in each of the three concepts in a profound and cryptic way. In my interpretation, the term describes the propensity of science based on the notion of physicalism to interpret nature as the machine analyzable and programmable by the human reason. As a result, the Anthropocene concept is built around the mechanicist model, which may be presented as the metaphor of the car without brakes. In a similar fashion, the Machinocene concept predicts the emergence of the mechanical mind, which will dominate nature in the near future. Finally, the Capitalocene concept turns a perfectly rational ambition to expand knowledge into an irrational obsession with over-knowledge, by employing the institutionalized science as the engine of capitalism without brakes. The common denominator of all three concepts is the irrational propensity to legitimize self-destruction. Potential avenues for countering the effects of “instrumental reason” are suggested
    corecore