120 research outputs found

    On string solutions of Bethe equations in N=4 supersymmetric Yang-Mills theory

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    The Bethe equations, arising in description of the spectrum of the dilatation operator for the su(2) sector of the N=4 supersymmetric Yang-Mills theory, are considered in the anti-ferromagnetic regime. These equations are deformation of those for the Heisenberg XXX magnet. It is proven that in the thermodynamic limit roots of the deformed equations group into strings. It is proven that the corresponding Yang's action is convex, which implies uniqueness of solution for centers of the strings. The state formed of strings of length (2n+1) is considered and the density of their distribution is found. It is shown that the energy of such a state decreases as n grows. It is observed that non-analyticity of the left hand side of the Bethe equations leads to an additional contribution to the density and energy of strings of even length. Whence it is concluded that the structure of the anti-ferromagnetic vacuum is determined by the behaviour of exponential corrections to string solutions in the thermodynamic limit and possibly involves strings of length 2.Comment: LaTex, 9 pages, 1 figur

    Predictors of internalised HIV-related stigma: a systematic review of studies in sub-Saharan Africa

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    This systematic review aims to synthesise evidence on predictors of internalised HIV stigma amongst people living with HIV in sub-Saharan Africa. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used. Studies were identified through electronic databases, grey literature, reference harvesting and contacts with key researchers. Quality of findings was assessed through an adapted version of the Cambridge Quality Checklists. A total of 590 potentially relevant titles were identified. Seventeen peer-reviewed articles and one draft book chapter were included. Studies investigated socio-demographic, HIV-related, intra-personal and interpersonal correlates of internalised stigma. Eleven articles used cross-sectional data, six articles used prospective cohort data and one used both prospective cohort and cross-sectional data to assess correlates of internalised stigma. Poor HIV-related health weakly predicted increases in internalised HIV stigma in three longitudinal studies. Lower depression scores and improvements in overall mental health predicted reductions in internalised HIV stigma in two longitudinal studies, with moderate and weak effects, respectively. No other consistent predictors were found. Studies utilising analysis of change and accounting for confounding factors are necessary to guide policy and programming but are scarce. High-risk populations, other stigma markers that might layer upon internalised stigma, and structural drivers of internalised stigma need to be examined

    Non-planar ABJM Theory and Integrability

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    Using an effective vertex method we explicitly derive the two-loop dilatation generator of ABJM theory in its SU(2)xSU(2) sector, including all non-planar corrections. Subsequently, we apply this generator to a series of finite length operators as well as to two different types of BMN operators. As in N=4 SYM, at the planar level the finite length operators are found to exhibit a degeneracy between certain pairs of operators with opposite parity - a degeneracy which can be attributed to the existence of an extra conserved charge and thus to the integrability of the planar theory. When non-planar corrections are taken into account the degeneracies between parity pairs disappear hinting the absence of higher conserved charges. The analysis of the BMN operators resembles that of N=4 SYM. Additional non-planar terms appear for BMN operators of finite length but once the strict BMN limit is taken these terms disappear.Comment: 1+26 pages, uses axodraw.sty. v2: typos fixed, references added. v3: more typos fixed, minor correction

    Finite size giant magnons in the SU(2) x SU(2) sector of AdS_4 x CP^3

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    We use the algebraic curve and Luscher's mu-term to calculate the leading order finite size corrections to the dispersion relation of giant magnons in the SU(2) x SU(2) sector of AdS_4 x CP^3. We consider a single magnon as well as one magnon in each SU(2). In addition the algebraic curve computation is generalized to give the leading order correction for an arbitrary multi-magnon state in the SU(2) x SU(2) sector.Comment: 19 pages; v2, v3: references added, typos fixe

    Quantum folded string and integrability: from finite size effects to Konishi dimension

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    Using the algebraic curve approach we one-loop quantize the folded string solution for the type IIB superstring in AdS(5)xS(5). We obtain an explicit result valid for arbitrary values of its Lorentz spin S and R-charge J in terms of integrals of elliptic functions. Then we consider the limit S ~ J ~ 1 and derive the leading three coefficients of strong coupling expansion of short operators. Notably, our result evaluated for the anomalous dimension of the Konishi state gives 2\lambda^{1/4}-4+2/\lambda^{1/4}. This reproduces correctly the values predicted numerically in arXiv:0906.4240. Furthermore we compare our result using some new numerical data from the Y-system for another similar state. We also revisited some of the large S computations using our methods. In particular, we derive finite--size corrections to the anomalous dimension of operators with small J in this limit.Comment: 20 pages, 1 figure; v2: references added, typos corrected; v3: major improvement of the references; v4: Discussion of short operators is restricted to the case n=1. This restriction does not affect the main results of the pape

    Semiclassical strings in AdS(3) X S^2

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    In this paper, we investigate the semiclassical strings in AdS(3)XS^2, in which the string configuration of AdS(3) is classified to three cases depending on the parameters. Each of these has a different anomalous dimension proportional to logS, S^(1/3) and S, where S is a angular momentum on AdS(3). Further we generalize the dispersion relations for various string configuration on AdS(3)XS^2.Comment: 15 pages, added reference

    The all loop AdS4/CFT3 Bethe ansatz

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    We propose a set of Bethe equations yielding the full asymptotic spectrum of the AdS4/CFT3 duality proposed in arXiv:0806.1218 to all orders in the t'Hooft coupling. These equations interpolate between the 2-loop Bethe ansatz of Minahan and Zarembo arXiv:0806.3951 and the string algebraic curve of arXiv:0807.0437. The several SU(2|2) symmetries of the theory seem to highly constrain the form of the Bethe equations up to a dressing factor whose form we also conjecture.Comment: References added. Factor of 2 in the discussion of the (generalized) scaling function fixe

    Worldsheet spectrum in AdS(4)/CFT(3) correspondence

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    The AdS(4)/CFT(3) duality is a new example of an integrable and exactly solvable AdS/CFT system. There is, however, a puzzling mismatch between the number of degrees of freedom used in the exact solution (4B+4F scattering states) and 8B+8F transverse oscillation modes of critical superstring theory. We offer a resolution of this puzzle by arguing that half of the string modes dissolve in the continuum of two-particle states once alpha' corrections are taken into account. We also check that the conjectured exact S-matrix of AdS(4)/CFT(3) agrees with the tree-level worldsheet calculation.Comment: 19 pages, 2 figures; v2: misprints in (2.3), (2.11) and (A.1) corrected, a reference added; v3: misprints in (B.6), (B.9) and (B.12) corrected; v4: footnote 4 adde

    Spinning strings at one-loop in AdS_4 x P^3

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    We analyze the folded spinning string in AdS_4 x P^3 with spin S in AdS_4 and angular momentum J in P^3. We calculate the one-loop correction to its energy in the scaling limit of both ln S and J large with their ratio kept fixed. This result should correspond to the first subleading strong coupling correction to the anomalous dimension of operators of the type Tr(D^S(Y^\dagger Y)^J) in the dual N=6 Chern-Simons-matter theory. Our result appears to depart from the predictions for the generalized scaling function found from the all-loop Bethe equations conjectured for this AdS_4/CFT_3 duality. We comment on the possible origin of this difference.Comment: 24 pages; v2: References added and typos correcte

    Spiky Strings in AdS(4) X CP**3 with Neveu-Schwarz Flux

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    We study general rotating string solution in the AdS(4) X CP**3 background with a B_NS holonomy turned on over CP1{\bf CP}^1 ⊂\subset CP3 {\bf CP}^3. We find the giant magnon and single spike solutions for the string moving in this background corresponding to open spin chain. We calculate the corresponding dispersion relation among various conserved charges for both the cases. We further study the finite size effect on both the giant magnon and single spike solutions.Comment: 12 pages,Minor modification,Published Version in JHE
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