969 research outputs found

    New vortex solution in SU(3) gauge-Higgs theory

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    Following a brief review of known vortex solutions in SU(N) gauge-adjoint Higgs theories we show the existence of a new ``minimal'' vortex solution in SU(3) gauge theory with two adjoint Higgs bosons. At a critical coupling the vortex decouples into two abelian vortices, satisfying Bogomol'nyi type, first order, field equations. The exact value of the vortex energy (per unit length) is found in terms of the topological charge that equals to the N=2 supersymmetric charge, at the critical coupling. The critical coupling signals the increase of the underlying supersymmetry.Comment: 15 page

    Solution of gauge theories induced by fundamental representation scalars

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    Gauge theories induced by scalars in the fundamental representation of the U(Nc)gauge×U(Nf)globalU(N_c)_{gauge}\times U(N_f)_{global} group are investigated in the large NcN_c and NfN_f limit. A master field is defined from bilinears of the scalar field following an Eguchi-Kawai type reduction of spacetime. The density function for the master field satisfies an integral equation that can be solved exactly in two dimensions (D=2) and in a convergent series of approximations at D>2D>2. While at D=2 the system is in the same phase at all Ï”=Nc/Nf\epsilon=N_c/N_f, it undergoes a phase transition at a critical value, Ï”c(D)\epsilon_c(D), for D>2D>2.Comment: 12 pages, LaTe

    The Color--Flavor Transformation of induced QCD

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    The Zirnbauer's color-flavor transformation is applied to the U(Nc)U(N_c) lattice gauge model, in which the gauge theory is induced by a heavy chiral scalar field sitting on lattice sites. The flavor degrees of freedom can encompass several `generations' of the auxiliary field, and for each generation, remaining indices are associated with the elementary plaquettes touching the lattice site. The effective, color-flavor transformed theory is expressed in terms of gauge singlet matrix fields carried by lattice links. The effective action is analyzed for a hypercubic lattice in arbitrary dimension. We investigate the corresponding d=2 and d=3 dual lattices. The saddle points equations of the model in the large-NcN_c limit are discussed.Comment: 24 pages, 6 figures, to appear in Int. J. Mod. Phys.

    Gauged Yukawa Matrix Models and 2-Dimensional Lattice Theories

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    We argue that chiral symmetry breaking in three dimensional QCD can be identified with N\'eel order in 2-dimensional quantum antiferromagnets. When operators which drive the chiral transition are added to these theories, we postulate that the resulting quantum critical behavior is in the universality class of gauged Yukawa matrix models. As a consequence, the chiral transition is typically of first order, although for a limited class of parameters it can be second order with computable critical exponents.Comment: LaTeX, 11 page

    Hamiltonian Study of Improved U(1U(1 Lattice Gauge Theory in Three Dimensions

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    A comprehensive analysis of the Symanzik improved anisotropic three-dimensional U(1) lattice gauge theory in the Hamiltonian limit is made. Monte Carlo techniques are used to obtain numerical results for the static potential, ratio of the renormalized and bare anisotropies, the string tension, lowest glueball masses and the mass ratio. Evidence that rotational symmetry is established more accurately for the Symanzik improved anisotropic action is presented. The discretization errors in the static potential and the renormalization of the bare anisotropy are found to be only a few percent compared to errors of about 20-25% for the unimproved gauge action. Evidence of scaling in the string tension, antisymmetric mass gap and the mass ratio is observed in the weak coupling region and the behaviour is tested against analytic and numerical results obtained in various other Hamiltonian studies of the theory. We find that more accurate determination of the scaling coefficients of the string tension and the antisymmetric mass gap has been achieved, and the agreement with various other Hamiltonian studies of the theory is excellent. The improved action is found to give faster convergence to the continuum limit. Very clear evidence is obtained that in the continuum limit the glueball ratio MS/MAM_{S}/M_{A} approaches exactly 2, as expected in a theory of free, massive bosons.Comment: 13 pages, 15 figures, submitted to Phys. Rev.

    Generalized Weyl solutions in d=5 Einstein-Gauss-Bonnet theory: the static black ring

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    We argue that the Weyl coordinates and the rod-structure employed to construct static axisymmetric solutions in higher dimensional Einstein gravity can be generalized to the Einstein-Gauss-Bonnet theory. As a concrete application of the general formalism, we present numerical evidence for the existence of static black ring solutions in Einstein-Gauss-Bonnet theory in five spacetime dimensions. They approach asymptotically the Minkowski background and are supported against collapse by a conical singularity in the form of a disk. An interesting feature of these solutions is that the Gauss-Bonnet term reduces the conical excess of the static black rings. Analogous to the Einstein-Gauss-Bonnet black strings, for a given mass the static black rings exist up to a maximal value of the Gauss-Bonnet coupling constant αâ€Č\alpha'. Moreover, in the limit of large ring radius, the suitably rescaled black ring maximal value of αâ€Č\alpha' and the black string maximal value of αâ€Č\alpha' agree.Comment: 43 pages, 14 figure

    New Universality Classes for Quantum Critical Behavior

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    We use the epsilon expansion to explore a new universality class of second order quantum phase transitions associated with a four-dimensional Yukawa field theory coupled to a traceless Hermitean matrix scalar field. We argue that this class includes four-fermi models in 2<D<42<D<4 dimensions with SU(NF)×U(N)SU(N_F)\times U(N) symmetry and a U(N) scalar, SU(NF)SU(N_F) iso-vector 4-fermi coupling. The epsilon expansion indicates that there is a second order phase transition for N≄N∗(NF)N\geq N^*(N_F), where N∗(NF)≃.27NFN^*(N_F)\simeq.27N_F if NF→∞N_F\to\infty.Comment: LaTeX, 9 pages, 1 tarred and uuencoded postscript figure. The new version contains information on the asymptotic dependence of the critical number of fermion species on $N_F

    Molecular mechanism of edema formation in nephrotic syndrome: therapeutic implications

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    Sodium retention and edema are common features of nephrotic syndrome that are classically attributed to hypovolemia and activation of the renin–angiotensin–aldosterone system. However, numbers of clinical and experimental findings argue against this underfill theory. In this review we analyze data from the literature in both nephrotic patients and experimental models of nephrotic syndrome that converge to demonstrate that sodium retention is not related to the renin–angiotensin–aldosterone status and that fluid leakage from capillary to the interstitium does not result from an imbalance of Starling forces, but from changes of the intrinsic properties of the capillary endothelial filtration barrier. We also discuss how most recent findings on the cellular and molecular mechanisms of sodium retention has allowed the development of an efficient treatment of edema in nephrotic patients
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