120 research outputs found
On string solutions of Bethe equations in N=4 supersymmetric Yang-Mills theory
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
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
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
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
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
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
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
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
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
We study general rotating string solution in the AdS(4) X CP**3 background
with a B_NS holonomy turned on over . 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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