17,321 research outputs found
Holographic Turbulence in Einstein-Gauss-Bonnet Gravity at Large
We study the holographic hydrodynamics in the Einstein-Gauss-Bonnet(EGB)
gravity in the framework of the large expansion. We find that the large
EGB equations can be interpreted as the hydrodynamic equations describing the
conformal fluid. These fluid equations are truncated at the second order of the
derivative expansion, similar to the Einstein gravity at large . From the
analysis of the fluid flows, we find that the fluid equations can be taken as a
variant of the compressible version of the non-relativistic Navier-Stokes
equations. Particularly, in the limit of small Mach number, these equations
could be cast into the form of the incompressible Navier-Stokes equations with
redefined Reynolds number and Mach number. By using numerical simulation, we
find that the EGB holographic turbulence shares similar qualitative feature as
the turbulence from the Einstein gravity, despite the presence of two extra
terms in the equations of motion. We analyze the effect of the GB term on the
holographic turbulence in detail.Comment: 30 pages, 11 figure
Illumination coding meets uncertainty learning: toward reliable AI-augmented phase imaging
We propose a physics-assisted deep learning (DL) framework for large space-bandwidth product (SBP) phase imaging. We design an asymmetric coded illumination scheme to encode high-resolution phase information across a wide field-of-view. We then develop a matching DL algorithm to provide large-SBP phase estimation. We show that this illumination coding scheme is highly scalable in achieving flexible resolution, and robust to experimental variations. We demonstrate this technique on both static and dynamic biological samples, and show that it can reliably achieve 5X resolution enhancement across 4X FOVs using only five multiplexed measurements -- more than 10X data reduction over the state-of-the-art. Typical DL algorithms tend to provide over-confident predictions, whose errors are only discovered in hindsight. We develop an uncertainty learning framework to overcome this limitation and provide predictive assessment to the reliability of the DL prediction. We show that the predicted uncertainty maps can be used as a surrogate to the true error. We validate the robustness of our technique by analyzing the model uncertainty. We quantify the effect of noise, model errors, incomplete training data, and "out-of-distribution" testing data by assessing the data uncertainty. We further demonstrate that the predicted credibility maps allow identifying spatially and temporally rare biological events. Our technique enables scalable AI-augmented large-SBP phase imaging with dependable predictions.Published versio
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