2 research outputs found
CFT dual of the AdS Dirichlet problem: Fluid/Gravity on cut-off surfaces
We study the gravitational Dirichlet problem in AdS spacetimes with a view to
understanding the boundary CFT interpretation. We define the problem as bulk
Einstein's equations with Dirichlet boundary conditions on fixed timelike
cut-off hypersurface. Using the fluid/gravity correspondence, we argue that one
can determine non-linear solutions to this problem in the long wavelength
regime. On the boundary we find a conformal fluid with Dirichlet constitutive
relations, viz., the fluid propagates on a `dynamical' background metric which
depends on the local fluid velocities and temperature. This boundary fluid can
be re-expressed as an emergent hypersurface fluid which is non-conformal but
has the same value of the shear viscosity as the boundary fluid. The
hypersurface dynamics arises as a collective effect, wherein effects of the
background are transmuted into the fluid degrees of freedom. Furthermore, we
demonstrate that this collective fluid is forced to be non-relativistic below a
critical cut-off radius in AdS to avoid acausal sound propagation with respect
to the hypersurface metric. We further go on to show how one can use this
set-up to embed the recent constructions of flat spacetime duals to
non-relativistic fluid dynamics into the AdS/CFT correspondence, arguing that a
version of the membrane paradigm arises naturally when the boundary fluid lives
on a background Galilean manifold.Comment: 71 pages, 2 figures. v2: Errors in bulk metrics dual to
non-relativistic fluids (both on cut-off surface and on the boundary) have
been corrected. New appendix with general results added. Fixed typos. 82
pages, 2 figure
ACE inhibitors and myocardial remodeling in patients with arterial hypertension and atrial fibrillation
The study is focused on assessing dynamics of left atrium volume and volume index after treatment of paroxysmal or persistent atrial fibrillation (AF), during ACE therapy with lipophilic (n=34) or hydrophilic (n=38) «standard» antihypertensive medications. After sinus rhythm restoration, mechanical dysfunction of left atrium was observed in 95, 8 % of the participants. Standard antihypertensive therapy, including lipophilic or hydrophilic ACE inhibitors, resulted in improved left atrium mechanical function and heart remodeling in 82, 1 %. Hydrophilic ACE inhibitor (Dapril) was no less effective than lipophilic medication (enalapril), being even more effective in terms of duration and dynamics of left atrium mechanical function recovery. Dapril demonstrated high effectiveness, no less than for enalapril, together with minimal adverse event rate (0 % vs 14 %>, respectively). This could improve patients' compliance to persistent medication therapy of the principal pathology