Tuning thermal transport in nanotubes with topological defects

Using the atomistic nonequilibrium Green's function, we find that thermal conductance of carbon nanotubes with presence of topological lattice imperfects is remarkably reduced, due to the strong Rayleigh scattering of high-frequency phonons. Phonon transmission across multiple defects behaves as a cascade scattering based with the random phase approximation. We elucidate that phonon scattering by structural defects is related to the spatial fluctuations of local vibrational density of states (LVDOS). An effective method of tuning thermal transport in low-dimensional systems through the modulation of LVDOS has been proposed. Our findings provide insights into experimentally controlling thermal transport in nanoscale devicesComment: 10 pages, 3 figure

Updated predictions for graviton and photon associated production at the LHC

We present updated predictions on the inclusive total cross sections, including the complete next-to-leading order QCD corrections, for the graviton and photon associated production process in the large extra dimensions model at the LHC with a center-of-mass energy of 7 and 8 TeV, using the parameters according to the requirements of the ATLAS and CMS Collaborations. Moreover, we also discuss in detail the dependence on the transverse momentum cut and uncertainties due to the choices of scales and parton distribution functions.Comment: 5 pages, 3 figures, 2 tables, version published in PR

Next-to-Leading-Order study on the associate production of J/ψ+γJ/\psi+\gamma at the LHC

The associate $J/\psi+\gamma$ production at the LHC is studied completely at next-to-leading-order (NLO) within the framework of nonrelativistic QCD. By using three sets of color-octet long-distance matrix elements (LDMEs) obtained in previous prompt $J/\psi$ studies, we find that only one of them can result in a positive transverse momentum ($p_t$) distribution of $J/\psi$ production rate at large $p_t$ region. Based on reasonable consideration to cut down background, our estimation is measurable upto $p_t=50$GeV with present data sample collected at $8$TeV LHC. All the color-octet LDMEs in $J/\psi$ production could be fixed sensitively by including this proposed measurement and our calculation, and then confident conclusion on $J/\psi$ polarization puzzle could be achieved.Comment: 5 pages, 2 figure

Identifying spatial invasion of pandemics on metapopulation networks via anatomizing arrival history

Spatial spread of infectious diseases among populations via the mobility of humans is highly stochastic and heterogeneous. Accurate forecast/mining of the spread process is often hard to be achieved by using statistical or mechanical models. Here we propose a new reverse problem, which aims to identify the stochastically spatial spread process itself from observable information regarding the arrival history of infectious cases in each subpopulation. We solved the problem by developing an efficient optimization algorithm based on dynamical programming, which comprises three procedures: i, anatomizing the whole spread process among all subpopulations into disjoint componential patches; ii, inferring the most probable invasion pathways underlying each patch via maximum likelihood estimation; iii, recovering the whole process by assembling the invasion pathways in each patch iteratively, without burdens in parameter calibrations and computer simulations. Based on the entropy theory, we introduced an identifiability measure to assess the difficulty level that an invasion pathway can be identified. Results on both artificial and empirical metapopulation networks show the robust performance in identifying actual invasion pathways driving pandemic spread.Comment: 14pages, 8 figures; Accepted by IEEE Transactions on Cybernetic

Next-to-next-to-leading order NN-jettiness soft function for tWtW production

We calculate the $N$-jettiness soft function for $tW$ production up to next-to-next-to-leading order in QCD, which is an important ingredient of the $N$-jettiness subtraction method for predicting the differential cross sections of massive coloured particle productions. The divergent parts of the results have been checked using the renormalization group equations controlled by the soft anomalous dimension.Comment: 14 pages, 3 figures, published version in PL

A Scalable CUR Matrix Decomposition Algorithm: Lower Time Complexity and Tighter Bound

The CUR matrix decomposition is an important extension of Nystr\"{o}m approximation to a general matrix. It approximates any data matrix in terms of a small number of its columns and rows. In this paper we propose a novel randomized CUR algorithm with an expected relative-error bound. The proposed algorithm has the advantages over the existing relative-error CUR algorithms that it possesses tighter theoretical bound and lower time complexity, and that it can avoid maintaining the whole data matrix in main memory. Finally, experiments on several real-world datasets demonstrate significant improvement over the existing relative-error algorithms.Comment: accepted by NIPS 201