8,330 research outputs found

    A Comprehensive Survey of Brane Tilings

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    An infinite class of 4d4d N=1\mathcal{N}=1 gauge theories can be engineered on the worldvolume of D3-branes probing toric Calabi-Yau 3-folds. This kind of setup has multiple applications, ranging from the gauge/gravity correspondence to local model building in string phenomenology. Brane tilings fully encode the gauge theories on the D3-branes and have substantially simplified their connection to the probed geometries. The purpose of this paper is to push the boundaries of computation and to produce as comprehensive a database of brane tilings as possible. We develop efficient implementations of brane tiling tools particularly suited for this search. We present the first complete classification of toric Calabi-Yau 3-folds with toric diagrams up to area 8 and the corresponding brane tilings. This classification is of interest to both physicists and mathematicians alike.Comment: 39 pages. Link to Mathematica modules provide

    Rare decays Bsβ†’l+lβˆ’B_s\to l^+l^- and Bβ†’Kl+lβˆ’B\to Kl^+l^- in \the topcolor-assisted technicolor model

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    We examine the rare decays Bsβ†’l+lβˆ’B_s\to l^+l^- and Bβ†’Kl+lβˆ’B\to Kl^+l^- in the framework of the topcolor-assisted technicolor (TC2TC2) model. The contributions of the new particles predicted by this model to these rare decay processes are evaluated. We find that the values of their branching ratios are larger than the standard model predictions by one order of magnitude in wide range of the parameter space. The longitudinal polarization asymmetry of leptons in Bsβ†’l+lβˆ’B_s \to l^+l^- can approach \ord(10^{-2}). The forward-backward asymmetry of leptons in Bβ†’Kl+lβˆ’B \to Kl^+l^- is not large enough to be measured in future experiments. We also give some discussions about the branching ratios and the asymmetry observables related to these rare decay processes in the littlest Higgs model with T-parity.Comment: 29 pages, 9 figure, corrected typos, the version to appear in PR

    The Effects of Minimal Length, Maximal Momentum and Minimal Momentum in Entropic Force

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    In this paper, the modified entropic force law is studied by using a new kind of generalized uncertainty principle which contains a minimal length, a minimal momentum and a maximal momentum. Firstly, the quantum corrections to the thermodynamics of a black hole is investigated. Then, according to Verlinde's theory, the generalized uncertainty principle (GUP) corrected entropic force is obtained. The result shows that the GUP corrected entropic force is related not only to the properties of the black holes, but also to the Planck length and the dimensionless constants Ξ±0\alpha _{\rm{0}} and Ξ²0\beta _{\rm{0}}. Moreover, based on the GUP corrected entropic force, we also derive the modified Einstein's field equation (EFE) and the modified Friedmann equation.Comment: 16 pages. arXiv admin note: substantial text overlap with arXiv:1604.0470

    Inverse Projection Representation and Category Contribution Rate for Robust Tumor Recognition

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    Sparse representation based classification (SRC) methods have achieved remarkable results. SRC, however, still suffer from requiring enough training samples, insufficient use of test samples and instability of representation. In this paper, a stable inverse projection representation based classification (IPRC) is presented to tackle these problems by effectively using test samples. An IPR is firstly proposed and its feasibility and stability are analyzed. A classification criterion named category contribution rate is constructed to match the IPR and complete classification. Moreover, a statistical measure is introduced to quantify the stability of representation-based classification methods. Based on the IPRC technique, a robust tumor recognition framework is presented by interpreting microarray gene expression data, where a two-stage hybrid gene selection method is introduced to select informative genes. Finally, the functional analysis of candidate's pathogenicity-related genes is given. Extensive experiments on six public tumor microarray gene expression datasets demonstrate the proposed technique is competitive with state-of-the-art methods.Comment: 14 pages, 19 figures, 10 table
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