283 research outputs found
Factorized Tree-level Scattering in AdS_4 x CP^3
AdS_4/CFT_3 duality relating IIA string theory on AdS_4 x CP^3 to N=6
superconformal Chern-Simons theory provides an arena for studying aspects of
integrability in a new potentially exactly solvable system. In this paper we
explore the tree-level worldsheet scattering for strings on AdS_4 x CP^3. We
compute all bosonic four-, five- and six-point amplitudes in the gauge-fixed
action and demonstrate the absence of particle production.Comment: 23 pages, v2. references adde
The Morphology of N=6 Chern-Simons Theory
We tabulate various properties of the language of N=6 Chern-Simons Theory, in
the sense of Polyakov. Specifically we enumerate and compute character formulas
for all syllables of up to four letters, i.e. all irreducible representations
of OSp(6|4) built from up to four fundamental fields of the ABJM theory. We
also present all tensor product decompositions for up to four singletons and
list the (cyclically invariant) four-letter words, which correspond to
single-trace operators of length four. As an application of these results we
use the two-loop dilatation operator to compute the leading correction to the
Hagedorn temperature of the weakly-coupled planar ABJM theory on R \times S^2.Comment: 41 pages, 1 figure; v2: minor correction
Strings in AdS_4 x CP^3: finite size spectrum vs. Bethe Ansatz
We compute the first curvature corrections to the spectrum of light-cone
gauge type IIA string theory that arise in the expansion of about a plane-wave limit. The resulting spectrum is shown to
match precisely, both in magnitude and degeneration that of the corresponding
solutions of the all-loop Gromov--Vieira Bethe Ansatz. The one-loop dispersion
relation correction is calculated for all the single oscillator states of the
theory, with the level matching condition lifted. It is shown to have all
logarithmic divergences cancelled and to leave only a finite exponentially
suppressed contribution, as shown earlier for light bosons. We argue that there
is no ambiguity in the choice of the regularization for the self-energy sum,
since the regularization applied is the only one preserving unitarity.
Interaction matrices in the full degenerate two-oscillator sector are
calculated and the spectrum of all two light magnon oscillators is completely
determined. The same finite-size corrections, at the order 1/J, where is
the length of the chain, in the two-magnon sector are calculated from the all
loop Bethe Ansatz. The corrections obtained by the two completely different
methods coincide up to the fourth order in . We
conjecture that the equivalence extends to all orders in and to
higher orders in 1/J.Comment: 32 pages. Published version; journal reference adde
Review of AdS/CFT Integrability, Chapter IV.3: N=6 Chern-Simons and Strings on AdS4xCP3
We review the duality and integrability of N=6 superconformal Chern-Simons
theory in three dimensions and IIA superstring theory on the background
AdS4xCP3. We introduce both of these models and describe how their degrees of
freedom are mapped to excitations of a long-range integrable spin-chain.
Finally, we discuss the properties of the Bethe equations, the S-matrix and the
algebraic curve that are special to this correspondence and differ from the
case of N=4 SYM theory and strings on AdS5xS5.Comment: 22 pages, see also overview article arXiv:1012.3982, v2: references
to other chapters updated, v3: references added, v4: brief discussion of
giant magnons added, further minor changes, published version, v5: union of
v3 and v4 because changes made in v3 were accidentally lost in v
Semiclassical Quantization of the Giant Magnon
Solitons in field theory provide a window into regimes not directly
accessible by the fundamental perturbative degrees of freedom. Motivated by
interest in the worldsheet S-matrix of string theory in AdS_5 x S^5 in the
limit of infinite worldsheet volume we consider the semiclassical quantization
of a particular soliton of this theory: the Hofman-Maldacena `giant magnon'
spinning string. We obtain explicit formulas for the complete spectrum of
bosonic and fermionic fluctuations around the giant magnon. As an application
of these results we confirm that the one-loop correction to the classical
energy vanishes as expected.Comment: 20 pages, JHEP3 style; v2: minor typos fixed and references adde
Multi-Regge kinematics and the moduli space of Riemann spheres with marked points
We show that scattering amplitudes in planar N = 4 Super Yang-Mills in
multi-Regge kinematics can naturally be expressed in terms of single-valued
iterated integrals on the moduli space of Riemann spheres with marked points.
As a consequence, scattering amplitudes in this limit can be expressed as
convolutions that can easily be computed using Stokes' theorem. We apply this
framework to MHV amplitudes to leading-logarithmic accuracy (LLA), and we prove
that at L loops all MHV amplitudes are determined by amplitudes with up to L +
4 external legs. We also investigate non-MHV amplitudes, and we show that they
can be obtained by convoluting the MHV results with a certain helicity flip
kernel. We classify all leading singularities that appear at LLA in the Regge
limit for arbitrary helicity configurations and any number of external legs.
Finally, we use our new framework to obtain explicit analytic results at LLA
for all MHV amplitudes up to five loops and all non-MHV amplitudes with up to
eight external legs and four loops.Comment: 104 pages, six awesome figures and ancillary files containing the
results in Mathematica forma
Conformal SO(2,4) Transformations for the Helical AdS String Solution
By applying the conformal SO(2,4) transformations to the folded rotating
string configuration with two spins given by a certain limit from the helical
string solution in AdS_3 x S^1, we construct new string solutions whose
energy-spin relations are characterized by the boost parameter. When two
SO(2,4) transformations are performed with two boost parameters suitably
chosen, the straight folded rotating string solution with one spin in AdS_3 is
transformed in the long string limit into the long spiky string solution whose
expression is given from the helical string solution in AdS_3 by making a limit
that the modulus parameter becomes unity.Comment: 16 pages, LaTex, no figure
A non-catecholamine-producing sympathetic paraganglioma of the spermatic cord: the importance of performing candidate gene mutation analysis
textabstractBackground: Catecholamine-producing tumours are called pheochromocytomas when they are located in the adrenal gland and sympathetic paragangliomas when they are located elsewhere in the abdomen. Rarely these tumours do not produce catecholamines and even more rarely they arise in the spermatic cord. Over the past decade, systematic mutation analysis of apparently sporadic cases of pheochromocytomas and paragangliomas has elucidated the frequent presence of germ line mutations in one of five candidate genes, including RET, VHL, SDHB, SDHC, and SDHD. Clinical history and methods: We describe a 45-year-old man with a non catecholamine-producing paraganglioma of the spermatic cord. We performed SDHB immunohistochemistry and performed mutation analysis of the SDHB, SDHC, and SDHD genes. Results: There was no staining of tumour cells with SDHB immunohistochemistry, indicative of an SDH mutation. Mutation analysis demonstrated a germ line SDHD mutation (p.Val147Met). Conclusions: Systematic mutation analysis is required in paraganglioma patients for the detection of germ line mutations. This should be preceded by SDHB immunohistochemistry to limit the number of genes to be tested
The association between sleeping time and metabolic syndrome features among older adults living in Mediterranean region. The MEDIS study.
Background: Metabolic Syndrome (MetS) as a combination of features has been known to significantly increase Cardiovascular Disease (CVD) risk, whilst MetS presence is linked to lifestyle parameters including physical activity and dietary habits; recently, the potential impact of sleeping habits has also become an issue under consideration. The aim of this study was to investigate the role of sleep quantity in several MetS components. Methods: Design:Cross-sectional observational study. Setting: 26 Mediterranean islands and the rural Mani region (Peloponnesus) of Greece. Participants: during 2005-2017, 3130 older (aged 65-100 years) Mediterranean residents were voluntarily enrolled. Measurements: Dietary habits (including MedDietScore assessment), physical activity status, socio-demographic characteristics, lifestyle parameters (sleeping and smoking habits) and clinical profile aspects including Metabolic Syndrome (MetS) components (i.e., waist circumference, systolic and diastolic blood pressure, fasting glucose, triglycerides, LDL and HDL-cholesterol) were derived through standard procedures. Results: The number of daily hours of sleep was independently associated with greater waist circumference (b coefficient per 1 hour=0.91, 95% Confidence Interval (CI); 0.34, 1.49), higher LDL-cholesterol levels (b per 1 hour=3.84, 95%CI; 0.63, 7.05) and lower diastolic blood pressure levels (b per 1 hour=-0.98, 95%CI; - 1.57, -0.39) after adjusting for participants’ age, gender, body mass index, daily walking time, level of adherence to Mediterranean diet and smoking status. No association was revealed between hours of sleep per day and fasting glucose, triglycerides, HDL-cholesterol and systolic blood pressure. Conclusions: Increased hours of sleep is an indicator of metabolic disorders among elderly inviduals, and further research is needed to identify the paths through which sleep quantity is linked to MetS features in different age-groups
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