10,606 research outputs found
Exciting LLM Geometries
We study excitations of LLM geometries. These geometries arise from the
backreaction of a condensate of giant gravitons. Excitations of the condensed
branes are open strings, which give rise to an emergent Yang-Mills theory at
low energy. We study the dynamics of the planar limit of these emergent gauge
theories, accumulating evidence that they are planar super
Yang-Mills. There are three observations supporting this conclusion: (i) we
argue for an isomorphism between the planar Hilbert space of the original
super Yang-Mills and the planar Hilbert space of the emergent
gauge theory, (ii) we argue that the OPE coefficients of the planar limit of
the emergent gauge theory vanish and (iii) we argue that the planar spectrum of
anomalous dimensions of the emergent gauge theory is that of planar super Yang-Mills. Despite the fact that the planar limit of the emergent
gauge theory is planar super Yang-Mills, we explain why the
emergent gauge theory is not super Yang-Mills theory.Comment: 30 pages plus Appendice
Non-Perturbative String Theory from AdS/CFT
The large expansion of giant graviton correlators is considered. Giant
gravitons are described using operators with a bare dimension of order . In
this case the usual expansion is not applicable and there are
contributions to the correlator that are non-perturbative in character. By
writing the (square of the) correlators in terms of the hypergeometric function
, we are able to rephrase the expansion of the
correlator as a semi-classical expansion for a Schr\"odinger equation. In this
way we are able to argue that the expansion of the correlator is Borel
summable and that it exhibits a parametric Stokes phenomenon as the angular
momentum of the giant graviton is varied.Comment: 33pages,no figure
Photoproduction of fully-charmed tetraquark at electron-ion colliders
In this work we investigate the inclusive photoproduction of the -odd
-wave fully-charmed tetraquark at electron-ion colliders within the
nonrelativistic QCD (NRQCD) factorization framework, at the lowest order in
velocity and . The value of the NRQCD long-distance matrix element is
estimated from two phenomenological potential models. Our studies reveal that
the photoproduction of fully-charmed tetraquark may be difficult to
observe at HERA and EicC, nevertheless its observation prospect at EIC appears
to be bright.Comment: 12 pages, 1 table, 3 figure
Efficacy of endoluminal interventional therapy in diabetic peripheral arterial occlusive disease: a retrospective trial
<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to assess the efficacy of interventional therapy for peripheral arterial occlusive disease and the difference between diabetic patients and non-diabetic patients.</p> <p>Methods</p> <p>139 consecutive patients between September 2006 and September 2010 who underwent percutaneous lower extremity revascularization for arterial lesions were divided into diabetes group (n = 62) and non-diabetes group (n = 77). Before intervention, rest ankle brachial indexes and three dimensional computed tomography angiography from abdominal aorta to tiptoe were performed. The interventional treatments included angioplasty with or without stenting. The clinical outcomes included rest ankle-brachial indexes, primary patency rates, secondary patency rates and limb-salvage rates for 6-month, 12-month, 24-month and 36-month after treatment. The primary and secondary patency rates of all interventions and the limb-salvage rates of the patients are illustrated by Kaplan-Meier curves and compared by log-rank analysis.</p> <p>Results</p> <p>The interventional operation success rates were 98.4% (61/62) in diabetes group and 100% (77/77) in non-diabetes group. The re-interventional operation success rates were 85.7% (18/21) in diabetes group and 76.9% (20/26) in non-diabetes group. The mean value of ankle brachial indexes was significantly increased after intervention (0.397 ± 0.125 versus 0.779 ± 0.137, t = -25.780, <it>P </it>< 0.001) in diabetes group and (0.406 ± 0.101 versus 0.786 ± 0.121, t = -37.221, <it>P </it>< 0.001) in non-diabetes group. Perioperative 30-day mortality was 0%. Major complications included groin hematoma in 7.2%, and pseudoaneurysm formation 2.2%. In diabetes group, 6, 12, 24, and 36-month primary patency rates were 88.7% ± 4.0%, 62.3% ± 6.6%, 55.3% ± 7.0%, and 46.5% ± 7.5%; secondary patency rates were 93.5% ± 3.1%, 82.3% ± 5.1%, 70.8% ± 6.5%, and 65.7% ± 7%; limb-salvage rates were 95.2% ± 2.7%, 87.7% ± 4.4%, 85.5% ± 4.8%, and 81.9% ± 5.8%. In non-diabetes group, 6, 12, 24, and 36-month primary patency rates were 90.9% ± 3.3%, 71.8% ± 5.4%, 71.8% ± 5.4%, and 60.9% ± 6.2%; secondary patency rates were 96.1% ± 2.2%, 91.6% ± 3.3%, 82.7% ± 4.8%, and 71.8% ± 6.2%; limb-salvage rates were 97.4% ± 1.8%, 94.4% ± 2.7%, 90.6% ± 3.7%, and 83.1% ± 5.4%. The differences between two groups were not significant (<it>P </it>> 0.05).</p> <p>Conclusion</p> <p>With a low risk of morbidity and mortality, the percutaneous revascularization accepted by patients does not affect ultimate necessary surgical revascularization and consequently should be considered as the preferred therapy for chronic lower extremity ischemia. The efficacy and prognosis of interventional therapy in diabetic patients is similar that in non-diabetic patients.</p
Model Spider: Learning to Rank Pre-Trained Models Efficiently
Figuring out which Pre-Trained Model (PTM) from a model zoo fits the target
task is essential to take advantage of plentiful model resources. With the
availability of numerous heterogeneous PTMs from diverse fields, efficiently
selecting the most suitable PTM is challenging due to the time-consuming costs
of carrying out forward or backward passes over all PTMs. In this paper, we
propose Model Spider, which tokenizes both PTMs and tasks by summarizing their
characteristics into vectors to enable efficient PTM selection. By leveraging
the approximated performance of PTMs on a separate set of training tasks, Model
Spider learns to construct tokens and measure the fitness score between a
model-task pair via their tokens. The ability to rank relevant PTMs higher than
others generalizes to new tasks. With the top-ranked PTM candidates, we further
learn to enrich task tokens with their PTM-specific semantics to re-rank the
PTMs for better selection. Model Spider balances efficiency and selection
ability, making PTM selection like a spider preying on a web. Model Spider
demonstrates promising performance in various configurations of model zoos
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