13,157,574 research outputs found

    I/O-Efficient Planar Range Skyline and Attrition Priority Queues

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    In the planar range skyline reporting problem, we store a set P of n 2D points in a structure such that, given a query rectangle Q = [a_1, a_2] x [b_1, b_2], the maxima (a.k.a. skyline) of P \cap Q can be reported efficiently. The query is 3-sided if an edge of Q is grounded, giving rise to two variants: top-open (b_2 = \infty) and left-open (a_1 = -\infty) queries. All our results are in external memory under the O(n/B) space budget, for both the static and dynamic settings: * For static P, we give structures that answer top-open queries in O(log_B n + k/B), O(loglog_B U + k/B), and O(1 + k/B) I/Os when the universe is R^2, a U x U grid, and a rank space grid [O(n)]^2, respectively (where k is the number of reported points). The query complexity is optimal in all cases. * We show that the left-open case is harder, such that any linear-size structure must incur \Omega((n/B)^e + k/B) I/Os for a query. We show that this case is as difficult as the general 4-sided queries, for which we give a static structure with the optimal query cost O((n/B)^e + k/B). * We give a dynamic structure that supports top-open queries in O(log_2B^e (n/B) + k/B^1-e) I/Os, and updates in O(log_2B^e (n/B)) I/Os, for any e satisfying 0 \le e \le 1. This leads to a dynamic structure for 4-sided queries with optimal query cost O((n/B)^e + k/B), and amortized update cost O(log (n/B)). As a contribution of independent interest, we propose an I/O-efficient version of the fundamental structure priority queue with attrition (PQA). Our PQA supports FindMin, DeleteMin, and InsertAndAttrite all in O(1) worst case I/Os, and O(1/B) amortized I/Os per operation. We also add the new CatenateAndAttrite operation that catenates two PQAs in O(1) worst case and O(1/B) amortized I/Os. This operation is a non-trivial extension to the classic PQA of Sundar, even in internal memory.Comment: Appeared at PODS 2013, New York, 19 pages, 10 figures. arXiv admin note: text overlap with arXiv:1208.4511, arXiv:1207.234

    O(αs)O(\alpha_s) Corrections to BXse+eB \to X_s e^+ e^- Decay in the 2HDM

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    O(αs)O(\alpha_s) QCD corrections to the inclusive BXse+eB \to X_s e^+ e^- decay are investigated within the two - Higgs doublet extension of the standard model (2HDM). The analysis is performed in the so - called off-resonance region; the dependence of the obtained results on the choice of the renormalization scale is examined in details. It is shown that O(αs)O(\alpha_s) corrections can suppress the BXse+eB \to X_s e^+ e^- decay width up to 1.5÷31.5 \div 3 times (depending on the choice of the dilepton invariant mass ss and the low - energy scale μ\mu). As a result, in the experimentally allowed range of the parameters space, the relations between the BXse+eB \to X_s e^+ e^- branching ratio and the new physics parameters are strongly affected. It is found also that though the renormalization scale dependence of the BXse+eB \to X_s e^+ e^- branching is significantly reduced, higher order effects in the perturbation theory can still be nonnegligible.Comment: 16 pages, latex, including 6 figures and 3 table

    Fractional ideals and integration with respect to the generalised Euler characteristic

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    Let bb be a fractional ideal of a one-dimensional Cohen-Macaulay local ring OO containing a perfect field kk. This paper is devoted to the study some OO-modules associated with bb. In addition, different motivic Poincar\'e series are introduced by considering ideal filtrations associated with bb; the corresponding functional equations of these Poincar\'e series are also described

    The Effects of the Massless O(alpha_s^2), O(\alpha\alpha_s), O(\alpha^2) QCD and QED Corrections and of the Massive Contributions to Gamma(H^0\rightarrow b\overline{b})

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    We consider in detail various theoretical uncertainties of the perturbative predictions for the decay width of H0bbH^0\rightarrow b\overline{b} process in the region 50 GeV<MH2MW50\ GeV< M_H\leq 2M_W. We calculate the order O(αs2)O(\alpha_s^2)-contributions to the expression for ΓHbb\Gamma_{Hb\overline{b}} through the pole quark mass and demonstrate that they are important for the elimination of the numerical difference between the corresponding expression and the one through the running bb-quark mass. The order O(ααs)O(\alpha\alpha_s) and O(α2)O(\alpha^2) massless and order O(mb2/MH2)O(m_b^2/M_H^2) massive corrections to ΓHbb\Gamma_{Hb\overline{b}} are also calculated. The importance of the latter contributions for modeling of the threshold effects is demonstrated. The troubles with identifying of the 4 recent L3 events e+el+lγγe^+e^-\rightarrow l^+l^-\gamma\gamma with the decay of a Standard Higgs boson are discussed.Comment: 16 pages, 6 figures (can be optained by mail after the request from the authers, e-mails: [email protected]; [email protected]); LATEX, modified version of ENSLAPP.-A.-407/92 preprin

    QCD Calculations of Heavy Quarkonium States

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    Recent results on the QCD analysis of bound states of heavy qˉq\bar{q}q quarks are reviewed, paying attention to what can be derived from the theory with a reasonable degree of rigour. We report a calculation of bˉc\bar{b}c bound states; a very precise evaluation of b,cb, c quark masses from quarkonium spectrum; the NNLO evaluation of Υe+e\Upsilon\to e^+e^-; and a discussion of power corrections. For the bb quark {\sl pole} mass we get, including O(mc2/mb2)O(m_c^2/m_b^2) and O(αs5logαs)O(\alpha_s^5\log \alpha_s) corrections, mb=5.020±0.058GeVm_b=5.020\pm0.058 GeV; and for the MSˉ\bar{MS} mass the result, correct to O(αs3)O(\alpha_s^3), O(mc2/mb2)O(m_c^2/m_b^2), mˉb(mˉb)=4.286±0.036GeV\bar{m}_b(\bar{m}_b)=4.286\pm0.036 GeV. For the decay Υe+e\Upsilon\to e^+e^-, higher corrections are too large to permit a reliable calculation, but we can predict a toponium width of 13±1keV13\pm1 keV.Comment: PlainTex file; one figur

    Creation and Growth of Components in a Random Hypergraph Process

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    Denote by an \ell-component a connected bb-uniform hypergraph with kk edges and k(b1)k(b-1) - \ell vertices. We prove that the expected number of creations of \ell-component during a random hypergraph process tends to 1 as \ell and bb tend to \infty with the total number of vertices nn such that =o(nb3)\ell = o(\sqrt[3]{\frac{n}{b}}). Under the same conditions, we also show that the expected number of vertices that ever belong to an \ell-component is approximately 121/3(b1)1/31/3n2/312^{1/3} (b-1)^{1/3} \ell^{1/3} n^{2/3}. As an immediate consequence, it follows that with high probability the largest \ell-component during the process is of size O((b1)1/31/3n2/3)O((b-1)^{1/3} \ell^{1/3} n^{2/3}). Our results give insight about the size of giant components inside the phase transition of random hypergraphs.Comment: R\'{e}sum\'{e} \'{e}tend
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