2,340 research outputs found

    On computation of the first Baues--Wirsching cohomology of a freely-generated small category

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    The Baues--Wirsching cohomology is one of the cohomologies of a small category. Our aim is to describe the first Baues--Wirsching cohomology of the small category generated by a finite quiver freely. We consider the case where the coefficient is a natural system obtained by the composition of a functor and the target functor. We give an algorithm to obtain generators of the vector space of inner derivations. It is known that there exists a surjection from the vector space of derivations of the small category to the first Baues--Wirsching cohomology whose kernel is the vector space of inner derivations.Comment: 11 page

    Conformal Turbulence with Boundary

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    Based upon the formalism of conformal field theory with a boundary, we give a description of the boundary effect on fully developed two dimensional turbulence. Exact one and two point velocity correlation functions and energy power spectrum confined in the upper half plane are obtained using the image method. This result enables us to address the infrared problem of the theory of conformal turbulence.Comment: 10pages, KHTP-93-01, SNUCTP-93-0

    Duality in Complex sine-Gordon Theory

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    New aspects of the complex sine-Gordon theory are addressed through the reformulation of the theory in terms of the gauged Wess-Zumino-Witten action. A dual transformation between the theory for the coupling constant \b > 0 and the theory for \b < 0 is given which agrees with the Krammers-Wannier duality in the context of perturbed conformal field theory. The B\"{a}cklund transform and the nonlinear superposition rule for the complex sine-Gordon theory are presented and from which, exact solutions, solitons and breathers with U(1) charge, are derived. We clarify topological and nontopological nature of neutral and charged solitons respectively, and discuss about the duality between the vector and the axial U(1) charges.Comment: 10 pages, LaTe

    Deformed Minimal Models and Generalized Toda Theory

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    We introduce a generalization of ArA_{r}-type Toda theory based on a non-abelian group G, which we call the (Ar,G)(A_{r},G)-Toda theory, and its affine extensions in terms of gauged Wess-Zumino-Witten actions with deformation terms. In particular, the affine (A1,SU(2))(A_{1},SU(2))-Toda theory describes the integrable deformation of the minimal conformal theory for the critical Ising model by the operator Φ(2,1)\Phi_{(2,1)}. We derive infinite conserved charges and soliton solutions from the Lax pair of the affine (A1,SU(2))(A_{1}, SU(2))-Toda theory. Another type of integrable deformation which accounts for the Φ(3,1)\Phi_{(3,1)}-deformation of the minimal model is also found in the gauged Wess-Zumino-Witten context and its infinite conserved charges are given.Comment: 11pages, SNUCTP 94-83 (One reference has been added.

    Health utility bias: A meta-analytic evaluation

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    A common assertion is that rating scale (RS) values are lower than both standard gamble (SG) and time tradeoff (TTO) values. However, differences among these methods may be due to method specific bias. While SG and TTO suffer systematic bias, RS responses are known to depend on the range and frequency of other health states being evaluated. Over many diverse studies this effect is predicted to diminish. Thus, a systematic review and data synthesis of RS-TTO and RS-SG difference scores may better reveal persistent dissimilarities. PURPOSE: To establish through systematic review and meta-analysis the net effect of biases that endure over many studies of utilities

    Classical Matrix sine-Gordon Theory

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    The matrix sine-Gordon theory, a matrix generalization of the well-known sine-Gordon theory, is studied. In particular, the A3A_{3}-generalization where fields take value in SU(2)SU(2) describes integrable deformations of conformal field theory corresponding to the coset SU(2)Ă—SU(2)/SU(2)SU(2) \times SU(2) /SU(2). Various classical aspects of the matrix sine-Gordon theory are addressed. We find exact solutions, solitons and breathers which generalize those of the sine-Gordon theory with internal degrees of freedom, by applying the Zakharov-Shabat dressing method and explain their physical properties. Infinite current conservation laws and the B\"{a}cklund transformation of the theory are obtained from the zero curvature formalism of the equation of motion. From the B\"{a}cklund transformation, we also derive exact solutions as well as a nonlinear superposition principle by making use of the Bianchi's permutability theorem.Comment: 25 pages, 6 Postscript figure

    Design and fabrication of double pancake coil using 2G wire for conduction cooled superconducting magnet

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    AbstractA large bore double pancake coil(DPC) was designed and tested with 2G HTS wire to develop the conduction cooled superconducting magnet with central field intensity of 3 T at 20K operating temperature and clear bore of 100mm at room temperature. The effect of insulation between turns of double pancake coils was tested. Two double pancake coils with and without turn to turn insulation were wound using 4mm wide 2G conductor. A temporary result suggests that the coil wound without electrical insulation can be protected from higher over current and shows improved stability

    Path Integral Bosonization of Massive GNO Fermions

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    We show the quantum equivalence between certain symmetric space sine-Gordon models and the massive free fermions. In the massless limit, these fermions reduce to the free fermions introduced by Goddard, Nahm and Olive (GNO) in association with symmetric spaces K/GK/G. A path integral formulation is given in terms of the Wess-Zumino-Witten action where the field variable gg takes value in the orthogonal, unitary, and symplectic representations of the group GG in the basis of the symmetric space. We show that, for example, such a path integral bosonization is possible when the symmetric spaces K/GK/G are SU(N)×SU(N)/SU(N);N≤3, Sp(2)/U(2)SU(N) \times SU(N)/SU(N); N \le 3, ~ Sp(2)/U(2) or SO(8)/U(4)SO(8)/U(4). We also address the relation between massive GNO fermions and the nonabelian solitons, and explain the restriction imposed on the fermion mass matrix due to the integrability of the bosonic model.Comment: 11 page

    Prospects of mass measurements for neutral MSSM Higgs bosons in the intense-coupling regime at a Linear Collider

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    We analyze the prospects for detecting the three neutral Higgs bosons of the Minimal Supersymmetric extension of the Standard Model in the intense-coupling regime at e+e- colliders. Due to the small mass differences between the Higgs states in this regime and their relative large total decay widths, the discrimination between the particles is challenging at the LHC and in some cases even impossible. We propose to use the missing mass technique in the Higgs-strahlung process in e+e- collisions to distinguish between the two CP-even Higgs eigenstates h and H, relying on their b b-bar decay in the b,b-bar,l+,l- event sample. Ah and AH associated production is then studied in the 4b-jet event sample to probe the CP-odd A boson. At collider energies sqrt(s) = 300 GeV and an integrated luminosity of 500 fb-1, accuracies in the mass measurement of the CP-even Higgs bosons are expected to range from 100 to 300 MeV, while for the CP-odd A boson, accuracies of less than 500 MeV can be obtained.Comment: 12 pages, 15 Postscript figure
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