43 research outputs found
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
Two-loop test of the N=6 Chern-Simons theory S-matrix
Starting from the integrable two-loop spin-chain Hamiltonian describing the
anomalous dimensions of scalar operators in the planar N=6 superconformal
Chern-Simons theory of ABJM, we perform a direct coordinate Bethe ansatz
computation of the corresponding two-loop S-matrix. The result matches with the
weak-coupling limit of the scalar sector of the all-loop S-matrix which we have
recently proposed. In particular, we confirm that the scattering of A and B
particles is reflectionless. As a warm up, we first review the analogous
computation of the one-loop S-matrix from the one-loop dilatation operator for
the scalar sector of planar N=4 superconformal Yang-Mills theory, and compare
the result with the all-loop SU(2|2)^{2} S-matrix.Comment: 21 pages, no figure; references adde
Dressed Giant Magnons on CP^3
A new example of AdS/CFT duality relating IIA string theory on AdS_4 x CP^3
to N=6 superconformal Chern-Simons theory has recently been provided by ABJM.
By now a number of papers have considered particular giant magnon classical
string solutions in the CP^3 background, corresponding to excitations in the
spin chain picture of the dual field theory. In this paper we apply the CP^3 =
SU(4)/S(U(3) x U(1)) dressing method to the problem of constructing general
classical string solutions describing various configurations of giant magnons.
As a particular application we present a new giant magnon solution on CP^3.
Interestingly the dressed solution carries only a single SO(6) charge, in
contrast with the dyonic magnons found in previous applications of the dressing
method.Comment: 13 pages, harvmac; v3: fixed misstatement of the dispersion
relation(!), v3: typos fixed and a few clarifying remarks adde
Giant Magnons on CP^3 by Dressing Method
We consider classical string spectrum of R x CP^3, and construct a family of
solutions with residual SU(2) symmetry by the dressing method on SU(4)/U(3)
sigma model. All of them obey the square-root type dispersion relation, as is
expected from the su(2|2) symmetry. A single dyonic giant magnon is not found
in this approach.Comment: 1+29 pages, 1 figure, v2: a figure and references added, minor
corrections, v3: remarks on semiclassical quantization added. To be published
in JHE
Scoping Review: Digital mental health interventions for children and adolescents affected by war
Objective
Over 200 million children and adolescents live in countries affected by violent conflict, are likely to have complex mental health needs, and struggle to access traditional mental health services. Digital mental health interventions have the potential to overcome some of the barriers in accessing mental health support. We performed a scoping review to map existing digital mental health interventions relevant for children and adolescents affected by war, examine the strength of the evidence base, and inform the development of future interventions.
Method
Based on a pre-registered strategy, we systematically searched MEDLINE, Embase, Global Health, APA PsychInfo, and Google Scholar from the creation of each database to 30th September 2022, identifying k=6,843 studies. Our systematic search was complemented by extensive consultation with experts from the GROW Network.
Results
The systematic search identified 6 relevant studies: one evaluating digital mental health interventions for children and adolescents affected by war and five for those affected by disasters. Experts identified 35 interventions of possible relevance. The interventions spanned from universal prevention to specialist-guided treatment. Most interventions directly targeted young people and parents/carers and were self-guided. A quarter of the interventions were tested through randomized controlled trials. Because most interventions were not culturally or linguistically adapted to relevant contexts, their implementation potential was unclear.
Conclusion
There is very limited evidence for the use of digital mental health interventions for children and adolescents affected by war at present. The review provides a framework to inform the development of new interventions
Giant Magnons in AdS4 x CP3: Embeddings, Charges and a Hamiltonian
This paper studies giant magnons in CP3, which in all known cases are old
solutions from S5 placed into two- and three-dimensional subspaces of CP3,
namely CP1, RP2 and RP3. We clarify some points about these subspaces, and
other potentially interesting three- and four-dimensional subspaces. After
confirming that E-(J1-J4)/2 is a Hamiltonian for small fluctuations of the
relevant 'vacuum' point particle solution, we use it to calculate the
dispersion relation of each of the inequivalent giant magnons. We comment on
the embedding of finite-J solutions, and use these to compare string solutions
to giant magnons in the algebraic curve.Comment: 17 pages (plus appendices) and 1 figure. v2 has new discussion of
placing finite-J giant magnons into CP^3, adds many references, and corrects
a few typo