10,448 research outputs found

    Light-cone Gauge Superstring Field Theory and Dimensional Regularization II

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    We propose a dimensional regularization scheme to deal with the divergences caused by colliding supercurrents inserted at the interaction points, in the light-cone gauge NSR superstring field theory. We formulate the theory in dd dimensions and define the amplitudes as analytic functions of dd. With an appropriately chosen three-string interaction term and large negative dd, the tree level amplitudes for the (NS,NS) closed strings can be recast into a BRST invariant form, using the superconformal field theory proposed in Ref.[arXiv:0911.3704]. We show that in the limit d→10d \to 10 they coincide with the results of the first quantized theory. Therefore we obtain the desired results without adding any contact interaction terms to the action.Comment: 23 pages; v2: minor modifications; v3: revised argument in section 3, added appendix C, results unchanged; v4: added clarifications, two figures and a footnote; v5: minor modification

    D-brane States and Disk Amplitudes in OSp Invariant Closed String Field Theory

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    We construct solitonic states in the OSp invariant string field theory, which are BRST invariant in the leading order of regularization parameter ϵ\epsilon. We calculate the disk amplitudes using these solitonic states and show that they describe D-branes and ghost D-branes.Comment: 37 pages, 8 figure

    Rumen Fermentation, Blood Metabolites, and Performance of Sheep Fed Tropical Browse Plants

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    The in vitro study was designed to evaluate total gas production, dry matter degradability (DMD), and VFA profile; while in vivo study was designed to evaluate nutrient intakes, blood metabolites, and performance of sheep fed native grass mixed with Calliandra calothyrrus (CC), Leucaena leucochepala (LL), Moringa oleifera (MO), Gliricidea sepium (GS), and Artocarpus heterophyllus (AH). The best three from the in vitro results were used to formulate diets in in vivo study. Sixteen male growing sheep (average BW 20 kg) were fed 100% native grass (NG) as control; 70% NG + 30% GS; 70% NG + 30% MO; and 70% NG + 30% AH. Nutrient consumptions, DMD, blood metabolites, and sheep performances were analyzed by using Completely Randomized Design. The in vitro results showed that the total gas production and DMD of CC and LL were the lowest (P<0.05) while the highest was found in GS, MO, and AH treatments (P<0.05). Meanwhile, the in vivo results showed that nutrient intakes (DM, CP, and CF) of GS and AH rations were the highest. The ADG, concentration of albumin, and globulin in all treatments were similar, while total serum protein, triglycerides, and glucose concentration in MO and AH rations were higher than others. Serum cholesterol concentration in MO ration was the lowest, meanwhile the concentration of IgG was the highest (P<0.05). Supplementation of 30% MO was the best choice for optimum rumen fermentation and maintaining health status of local sheep

    Epitaxial designs for maximizing efficiency in resonant tunnelling diode based terahertz emitters

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    We discuss the modelling of high current density InGaAs/AlAs/InP resonant tunneling diodes to maximize their efficiency as THz emitters. A figure of merit which contributes to the wall plug efficiency, the intrinsic resonator efficiency, is used for the development of epitaxial designs. With the contribution of key parameters identified, we analyze the limitations of accumulated stress to assess the manufacturability of such designs. Optimal epitaxial designs are revealed, utilizing thin barriers, with a wide and shallow quantum well that satisfies the strained layer epitaxy constraint. We then assess the advantages to epitaxial perfection and electrical characteristics provided by devices with a narrow InAs sub-well inside a lattice-matched InGaAs alloy. These new structures will assist in the realization of the next-generation submillimeter emitters
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