Universal properties of thermal and electrical conductivity of gauge theory plasmas from holography

We propose that for conformal field theories admitting gravity duals, the thermal conductivity is fixed by the central charges in a universal manner. Though we do not have a proof as yet, we have checked our proposal against several examples. This proposal, if correct, allows us to express electrical conductivity in terms of thermodynamical quantities even in the presence of chemical potential.Comment: 13 pages, appendix added, close to journal versio

Shear sum rules at finite chemical potential

We derive sum rules which constrain the spectral density corresponding to the retarded propagator of the T_{xy} component of the stress tensor for three gravitational duals. The shear sum rule is obtained for the gravitational dual of the N=4 Yang-Mills, theory of the M2-branes and M5-branes all at finite chemical potential. We show that at finite chemical potential there are additional terms in the sum rule which involve the chemical potential. These modifications are shown to be due to the presence of scalars in the operator product expansion of the stress tensor which have non-trivial vacuum expectation values at finite chemical potential.Comment: The proof for the absence of branch cuts is corrected.Results unchange

TCT-378 Not Every TEE Is a “Standard of Care” TEE

Background: Intraprocedural structural heart imaging is more challenging and has unique differences from standard of care (SOC) imaging. However, the variations in time and complexity of different types of SOC transesophageal echocardiographs (TEEs) versus interventional TEEs is not well studied. In this study, we aim to compare the complexity of SOC nonvalvular indication TEE with SOC valvular TEE studies and interventional TEEs performed in the guidance of transcatheter edge-to-edge repair (TEER) MitraClip (Abbott Vascular) procedures. Methods: A retrospective case-control analysis was performed on 200 patients who underwent TEE in the Henry Ford Health System. One hundred cases of interventional TEE-guided TEER were compared with 73 nonvalvular (endocarditis and stroke evaluation) SOC TEEs and 27 valvular (preprocedural mitral, aortic, and tricuspid valve evaluations) SOC TEEs. Complexity was quantified by the total procedure duration, the total number of images, and the number of 3-dimensional (3D) clips captured. The mean, median, and SD were compared between these groups. The Kruskal-Wallis test was used to evaluate statistical significance. Results: The mean duration of TEE procedures, the number of images, and the number of 3D clips were all significantly higher in the interventional imaging TEER group compared with the noninterventional groups (P \u3c 0.0001) (Table 1). The duration and number of images were also significantly higher among valvular compared with nonvalvular SOC TEE groups (P \u3c 0.0002) as well as number of 3D clips (P \u3c 0.0012). Conclusion: Interventional TEE was more complicated and time-consuming compared with SOC TEE performed for both nonvalvular and valvular indications. The latter was also more complex than SOC nonvalvular TEE. This is the first study of its kind demonstrating objective differences between interventional and 2 SOC TEE groups. These results emphasize the need of dedicated training for intraprocedural imaging as well as restructuring of reimbursement codes. Categories: STRUCTURAL: Valvular Disease: Mitra

TCT-374 Structural Heart Intraprocedural Versus Nonprocedural Transesophageal Echocardiography: A Quantitative Analysis of Complexity

Background: Transesophageal echocardiography (TEE) is an essential tool in many structural heart procedures, such as transcatheter mitral valve edge-to-edge repair (TEER). Interventional procedural TEE requires a unique skill set. This study aims to evaluate the complexity of interventional structural heart TEE used to guide TEER compared with standard of care (SOC) TEE studies performed at a single center. Methods: A retrospective case-control analysis was performed of 200 patients who underwent TEE in the Henry Ford Health System. One hundred cases of interventional TEE-guided TEER were compared with 100 controls of SOC TEE. Complexity was quantified by the total duration of the procedure, the total number of images, and the number of 3-dimensional clips captured. The mean, median, and SD were compared between these 2 groups. Wilcoxon rank sum tests were used to evaluate statistical significance. Results: One hundred intraprocedural TEE studies to guide TEER and 100 SOC TEE studies were analyzed. The mean duration of TEE procedures, the number of images, and the number of 3-dimensional clips were all significantly higher in the TEER group (P \u3c 0.0001) (Table 1). Conclusion: Interventional TEE guidance for TEER is significantly more complex and more time-consuming than SOC TEE. This is the first large-scale study demonstrating objective differences between interventional and SOC TEE. This conclusion implicates the necessity of dedicated training programs for interventional imaging, in addition to the necessity of reviewing the current reimbursement codes to account for such a difference. Categories: STRUCTURAL: Valvular Disease: Mitra

Universal thermal and electrical conductivity from holography

It is known from earlier work of Iqbal, Liu (arXiv:0809.3808) that the boundary transport coefficients such as electrical conductivity (at vanishing chemical potential), shear viscosity etc. at low frequency and finite temperature can be expressed in terms of geometrical quantities evaluated at the horizon. In the case of electrical conductivity, at zero chemical potential gauge field fluctuation and metric fluctuation decouples, resulting in a trivial flow from horizon to boundary. In the presence of chemical potential, the story becomes complicated due to the fact that gauge field and metric fluctuation can no longer be decoupled. This results in a nontrivial flow from horizon to boundary. Though horizon conductivity can be expressed in terms of geometrical quantities evaluated at the horizon, there exist no such neat result for electrical conductivity at the boundary. In this paper we propose an expression for boundary conductivity expressed in terms of geometrical quantities evaluated at the horizon and thermodynamical quantities. We also consider the theory at finite cutoff outside the horizon (arXiv:1006.1902) and give an expression for cutoff dependent electrical conductivity, which interpolates smoothly between horizon conductivity and boundary conductivity . Using the results about the electrical conductivity we gain much insight into the universality of thermal conductivity to viscosity ratio proposed in arXiv:0912.2719.Comment: An appendix added discussing relation between boundary conductivity and universal conductivity of stretched horizon, version to be published in JHE