1,858 research outputs found

    Spontaneous Symmetry Breaking at Infinite Momentum without P+ Zero-Modes

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    The nonrelativistic interpretation of quantum field theory achieved by quantization in an infinite momentum frame is spoiled by the inclusion of a mode of the field carrying p+=0. We therefore explore the viability of doing without such a mode in the context of spontaneous symmetry breaking (SSB), where its presence would seem to be most needed. We show that the physics of SSB in scalar quantum field theory in 1+1 space-time dimensions is accurately described without a zero-mode.Comment: LaTeX, 8 pages, 3 eps figure

    The Outburst of the Blazar AO 0235+164 in 2006 December: Shock-in-Jet Interpretation

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    We present the results of polarimetric (RR band) and multicolor photometric (BVRIJHKBVRIJHK) observations of the blazar AO 0235+16 during an outburst in 2006 December. The data reveal a short timescale of variability (several hours), which increases from optical to near-IR wavelengths; even shorter variations are detected in polarization. The flux density correlates with the degree of polarization, and at maximum degree of polarization the electric vector tends to align with the parsec-scale jet direction. We find that a variable component with a steady power-law spectral energy distribution and very high optical polarization (30-50%) is responsible for the variability. We interpret these properties of the blazar withina model of a transverse shock propagating down the jet. In this case a small change in the viewing angle of the jet, by â‰Č1o\lesssim 1^o, and a decrease in the shocked plasma compression by a factor of ∌\sim1.5 are sufficient to account for the variability.Comment: 22 pages, 8 figures, accepted for Ap

    Kiwi talent flow : a study of chartered accountants and business professionals overseas

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    New Zealanders have always had a propensity to travel overseas. The globalisation of the world has seen an increase in the number of people who, having completed their education and gained some work experience, set off on their overseas experience. Concern has been expressed as to the potential “brain drain” that would result should these well-educated and talented citizens remain overseas permanently. This research considers the propensity to return of over 1,500 expatriate Kiwis working in the areas of accounting and finance. It examines their demographics, attitudes, values, motivations, factors of attraction to, and repulsion from, New Zealand and their concerns for change in New Zealand. It therefore provides insights into the nature and purpose of this significant group of professionals resident mainly in the United Kingdom and Australia. We find that less than half are likely to return to New Zealand. This is because of the lack of career and business opportunities despite the “pull” of family and relations in New Zealand

    Small x divergences in the Similarity RG approach to LF QCD

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    We study small x divergences in boost invariant similarity renormalization group approach to light-front QCD in a heavy quark-antiquark state. With the boost invariance maintained, the infrared divergences do not cancel out in the physical states, contrary to previous studies where boost invariance was violated by a choice of a renormalization scale. This may be an indication that the zero mode, or nontrivial light-cone vacuum structure, might be important for recovering full Lorentz invariance.Comment: 23 pgs, 1 fig. Revised for publication: typos corrected, improved discussion of regularizatio

    Fine-Tuning Renormalization and Two-particle States in Nonrelativistic Four-fermion Model

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    Various exact solutions of two-particle eigenvalue problems for nonrelativistic contact four-fermion current-current interaction are obtained. Specifics of Goldstone mode is investigated. The connection between a renormalization procedure and construction of self-adjoint extensions is revealed.Comment: 13 pages, LaTex, no figures, to be published in IJMP

    Renormalization in Quantum Mechanics

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    We implement the concept of Wilson renormalization in the context of simple quantum mechanical systems. The attractive inverse square potential leads to a \b function with a nontrivial ultraviolet stable fixed point and the Hulthen potential exhibits the crossover phenomenon. We also discuss the implementation of the Wilson scheme in the broader context of one dimensional potential problems. The possibility of an analogue of Zamolodchikov's CC function in these systems is also discussed.Comment: 16 pages, UR-1310, ER-40685-760. (Additional references included.

    From Free Fields to AdS -- II

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    We continue with the program of hep-th/0308184 to implement open-closed string duality on free gauge field theory (in the large NN limit). In this paper we consider correlators such as \la \prod_{i=1}^n \Tr\Phi^{J_i}(x_i)\ra. The Schwinger parametrisation of this nn-point function exhibits a partial gluing up into a set of basic skeleton graphs. We argue that the moduli space of the planar skeleton graphs is exactly the same as the moduli space of genus zero Riemann surfaces with nn holes. In other words, we can explicitly rewrite the nn-point (planar) free field correlator as an integral over the moduli space of a sphere with nn holes. A preliminary study of the integrand also indicates compatibility with a string theory on AdSAdS. The details of our argument are quite insensitive to the specific form of the operators and generalise to diagrams of higher genus as well. We take this as evidence of the field theory's ability to reorganise itself into a string theory.Comment: 26 pages, 2 figures; v2. some additional comments, references adde

    Three-particle States in Nonrelativistic Four-fermion Model

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    On a nonrelativistic contact four-fermion model we have shown that the simple Lambda-cut-off prescription together with definite fine-tuning of the Lambda dependency of "bare"quantities lead to self-adjoint semi-bounded Hamiltonian in one-, two- and three-particle sectors. The fixed self-adjoint extension and exact solutions in two-particle sector completely define three-particle problem. The renormalized Faddeev equations for the bound states with Fredholm properties are obtained and analyzed.Comment: 9 pages, LaTex, no figure
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