Scalable Task-Based Algorithm for Multiplication of Block-Rank-Sparse Matrices

A task-based formulation of Scalable Universal Matrix Multiplication Algorithm (SUMMA), a popular algorithm for matrix multiplication (MM), is applied to the multiplication of hierarchy-free, rank-structured matrices that appear in the domain of quantum chemistry (QC). The novel features of our formulation are: (1) concurrent scheduling of multiple SUMMA iterations, and (2) fine-grained task-based composition. These features make it tolerant of the load imbalance due to the irregular matrix structure and eliminate all artifactual sources of global synchronization.Scalability of iterative computation of square-root inverse of block-rank-sparse QC matrices is demonstrated; for full-rank (dense) matrices the performance of our SUMMA formulation usually exceeds that of the state-of-the-art dense MM implementations (ScaLAPACK and Cyclops Tensor Framework).Comment: 8 pages, 6 figures, accepted to IA3 2015. arXiv admin note: text overlap with arXiv:1504.0504

Z_{12-I} Orbifold Compactification toward SUSY Standard Model

We explain the orbifold compactification in string models and present a Z_{12-I} orbifold compactification toward supersymmetric standard models. We also point out an effective R-parity from this string construction. The VEVs of gauge singlets are chosen such that phenomenological constraints are satisfied.Comment: 13 pages with 5 figure. Talk presented at "CTP Symposium on SUSY at LHC", Cairo, 11-14 March 200

Charmonium levels near threshold and the narrow state X(3872) \to \pi^{+}\pi^{-}\jpsi

We explore the influence of open-charm channels on charmonium properties, and profile the 1:3D2, 1:3D3 and 2:1P1 charmonium candidates for X(3872). The favored candidates, the 1:3D2 and 1:3D3 levels, both have prominent radiative decays. The 1:3D2 might be visible in the $D^{0}\bar{D}^{*0}$ channel, while the dominant decay of the 1:3D3 state should be into $D\bar{D}$. We propose that additional discrete charmonium levels can be discovered as narrow resonances of charmed and anticharmed mesons.Comment: 8 pages, 6 figures, uses RevTeX and boxedeps; few transcription errors corrected in Tables IV and VI, three entries added in Table V, updated references. Version to appear in Phys. Rev.

Dynamic transition and Shapiro-step melting in a frustrated Josephson-junction array

We consider a two-dimensional fully frustrated Josephson-junction array driven by combined direct and alternating currents. Interplay between the mode locking phenomenon, manifested by giant Shapiro steps in the current-voltage characteristics, and the dynamic phase transition is investigated at finite temperatures. Melting of Shapiro steps due to thermal fluctuations is shown to be accompanied by the dynamic phase transition, the universality class of which is also discussed

Variation in Boilerplate: Rational Design or Random Mutation?

Standard contract doctrine presumes that sophisticated parties choose their terminology carefully because they want courts or counterparts to understand what they intended. The implication of this “Rational Design” model of rational behavior is that courts should pay careful attention to the precise phrasing of contracts. Using a study of the sovereign bond market, we examine the Rational Design model as applied to standard-form contracting. In NML v. Argentina, federal courts in New York attached importance to the precise phrasing of the boilerplate contracts at issue. The industry promptly condemned the decision for a supposedly erroneous interpretation of a variant of a hoary boilerplate clause. Utilizing data on how contracting practices responded to the decision, we ask whether the market response indicates that parties in fact intended for the small variations in their contract language to embody a particular meaning. We find the data supports a model closer to random mutation rather than rational design

Leptogenesis origin of Dirac gaugino dark matter

The Dirac nature of the gauginos (and also the Higgsinos) can be realized in $R$-symmetric supersymmetry models. In this class of models, the Dirac bino (or wino) with a small mixture of the Dirac Higgsinos is a good dark matter candidate. When the seesaw mechanism with Higgs triplet superfields is implemented to account for the neutrino masses and mixing, the leptogenesis driven by the heavy triplet decay is shown to produce not only the matter-antimatter asymmetry but also the asymmetric relic density of the Dirac gaugino dark matter. The dark matter mass turns out to be controlled by the Yukawa couplings of the heavy Higgs triplets, and it can be naturally at the weak scale for a mild hierarchy of the Yukawa couplings.Comment: 9 pages. Restructured for clear presentation, corrected some errors and typos. No change in conclusio

Low-frequency method for magnetothermopower and Nernst effect measurements on single crystal samples at low temperatures and high magnetic fields

We describe an AC method for the measurement of the longitudinal (Sxx) and transverse (Sxy, i.e. Nernst) thermopower of mm-size single crystal samples at low temperatures (T30 T). A low-frequency (33 mHz) heating method is used to increase the resolution, and to determine the temperature gradient reliably in high magnetic fields. Samples are mounted between two thermal blocks which are heated by a sinusoidal frequency f0 with a p/2 phase difference. The phase difference between two heater currents gives a temperature gradient at 2f0. The corresponding thermopower and Nernst effect signals are extracted by using a digital signal processing method due. An important component of the method involves a superconducting link, YBa2Cu3O7+d (YBCO), which is mounted in parallel with sample to remove the background magnetothermopower of the lead wires. The method is demonstrated for the quasi two-dimensional organic conductor a-(BEDT-TTF)2KHg(SCN)4, which exhibits a complex, magnetic field dependent ground state above 22.5 T at low temperatures.Comment: 11 pages, 6 figures, 15 reference

Targeting kidney mesangium by nanoparticles of defined size

Nanoparticles are being investigated for numerous medical applications and are showing potential as an emerging class of carriers for drug delivery. Investigations on how the physicochemical properties (e.g., size, surface charge, shape, and density of targeting ligands) of nanoparticles enable their ability to overcome biological barriers and reach designated cellular destinations in sufficient amounts to elicit biological efficacy are of interest. Despite proven success in nanoparticle accumulation at cellular locations and occurrence of downstream therapeutic effects (e.g., target gene inhibition) in a selected few organs such as tumor and liver, reports on effective delivery of engineered nanoparticles to other organs still remain scarce. Here, we show that nanoparticles of ~75 ± 25-nm diameters target the mesangium of the kidney. These data show the effects of particle diameter on targeting the mesangium of the kidney. Because many diseases originate from this area of the kidney, our findings establish design criteria for constructing nanoparticle-based therapeutics for targeting diseases that involve the mesangium of the kidney