187,705 research outputs found

    On a class of reductions of Manakov-Santini hierarchy connected with the interpolating system

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    Using Lax-Sato formulation of Manakov-Santini hierarchy, we introduce a class of reductions, such that zero order reduction of this class corresponds to dKP hierarchy, and the first order reduction gives the hierarchy associated with the interpolating system introduced by Dunajski. We present Lax-Sato form of reduced hierarchy for the interpolating system and also for the reduction of arbitrary order. Similar to dKP hierarchy, Lax-Sato equations for LL (Lax fuction) due to the reduction split from Lax-Sato equations for MM (Orlov function), and the reduced hierarchy for arbitrary order of reduction is defined by Lax-Sato equations for LL only. Characterization of the class of reductions in terms of the dressing data is given. We also consider a waterbag reduction of the interpolating system hierarchy, which defines (1+1)-dimensional systems of hydrodynamic type.Comment: 15 pages, revised and extended, characterization of the class of reductions in terms of the dressing data is give

    Yukawa Corrections from Four-Point Functions in Intersecting D6-Brane Models

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    We discuss corrections to the Yukawa matrices of the Standard Model (SM) fermions in intersecting D-brane models due to four-point interactions. Recently, an intersecting D-brane model has been found where it is possible to obtain correct masses and mixings for all quarks as well as the tau lepton. However, the masses for the first two charged leptons come close to the right values but are not quite correct. Since the electron and muon are quite light, it is likely that there are additional corrections to their masses which cannot be neglected. With this in mind, we consider contributions to the SM fermion mass matrices from four-point interactions. In an explicit model, we show that it is indeed possible to obtain the SM fermion masses and mixings which are a better match to those resulting from experimental data extrapolated at the unification scale when these corrections are included. These corrections may have broader application to other models.Comment: 24 pages, 4 figure

    Landscape phage, phage display, stripped phage, biosensors, detection, affinity reagent, nanotechnology, Salmonella typhimurium, Bacillus anthracis

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    Filamentous phage, such as fd used in this study, are thread-shaped bacterial viruses. Their outer coat is a tube formed by thousands equal copies of the major coat protein pVIII. We constructed libraries of random peptides fused to all pVIII domains and selected phages that act as probes specific for a panel of test antigens and biological threat agents. Because the viral carrier is infective, phage borne bio-selective probes can be cloned individually and propagated indefinitely without needs of their chemical synthesis or reconstructing. We demonstrated the feasibility of using landscape phages and their stripped fusion proteins as new bioselective materials that combine unique characteristics of affinity reagents and self assembling membrane proteins. Biorecognition layers fabricated from phage-derived probes bind biological agents and generate detectable signals. The performance of phage-derived materials as biorecognition films was illustrated by detection of streptavidin-coated beads, Bacillus anthracis spores and Salmonella typhimurium cells. With further refinement, the phage-derived analytical platforms for detecting and monitoring of numerous threat agents may be developed, since the biodetector films may be obtained from landscape phages selected against any bacteria, virus or toxin. As elements of field-use detectors, they are superior to antibodies, since they are inexpensive, highly specific and strong binders, resistant to high temperatures and environmental stresses.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

    A Supersymmetric Flipped SU(5) Intersecting Brane World

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    We construct an N=1 supersymmetric three-family flipped SU(5) model from type IIA orientifolds on T6/(Z2×Z2)T^6/(\Z_2\times \Z_2) with D6-branes intersecting at general angles. The spectrum contains a complete grand unified and electroweak Higgs sector. In addition, it contains extra exotic matter both in bi-fundamental and vector-like representations as well as two copies of matter in the symmetric representation of SU(5).Comment: 17 pages, 3 tables, v2 published in Phys.Lett.

    Stack and Queue Layouts via Layered Separators

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    It is known that every proper minor-closed class of graphs has bounded stack-number (a.k.a. book thickness and page number). While this includes notable graph families such as planar graphs and graphs of bounded genus, many other graph families are not closed under taking minors. For fixed gg and kk, we show that every nn-vertex graph that can be embedded on a surface of genus gg with at most kk crossings per edge has stack-number O(logn)\mathcal{O}(\log n); this includes kk-planar graphs. The previously best known bound for the stack-number of these families was O(n)\mathcal{O}(\sqrt{n}), except in the case of 11-planar graphs. Analogous results are proved for map graphs that can be embedded on a surface of fixed genus. None of these families is closed under taking minors. The main ingredient in the proof of these results is a construction proving that nn-vertex graphs that admit constant layered separators have O(logn)\mathcal{O}(\log n) stack-number.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

    Non-analyticity of the groud state energy of the Hamiltonian for Hydrogen atom in non-relativistic QED

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    We derive the ground state energy up to the fourth order in the fine structure constant α\alpha for the translation invariant Pauli-Fierz Hamiltonian for a spinless electron coupled to the quantized radiation field. As a consequence, we obtain the non-analyticity of the ground state energy of the Pauli-Fierz operator for a single particle in the Coulomb field of a nucleus

    Ground state energy of unitary fermion gas with the Thomson Problem approach

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    The dimensionless universal coefficient ξ\xi defines the ratio of the unitary fermions energy density to that for the ideal non-interacting ones in the non-relativistic limit with T=0. The classical Thomson Problem is taken as a nonperturbative quantum many-body arm to address the ground state energy including the low energy nonlinear quantum fluctuation/correlation effects. With the relativistic Dirac continuum field theory formalism, the concise expression for the energy density functional of the strongly interacting limit fermions at both finite temperature and density is obtained. Analytically, the universal factor is calculated to be ξ=4/9\xi={4/9}. The energy gap is \Delta=\frac{{5}{18}{k_f^2}/(2m).Comment: Identical to published version with revisions according to comment
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