49,377 research outputs found
Entanglement renormalization and integral geometry
We revisit the applications of integral geometry in AdS and argue that
the metric of the kinematic space can be realized as the entanglement contour,
which is defined as the additive entanglement density. From the renormalization
of the entanglement contour, we can holographically understand the operations
of disentangler and isometry in multi-scale entanglement renormalization
ansatz. Furthermore, a renormalization group equation of the long-distance
entanglement contour is then derived. We then generalize this integral
geometric construction to higher dimensions and in particular demonstrate how
it works in bulk space of homogeneity and isotropy.Comment: 40 pages, 7 figures. v2: discussions on the general measure added,
typos fixed; v3: sections reorganized, various points clarified, to appear in
JHE
OPE of the stress tensors and surface operators
We demonstrate that the divergent terms in the OPE of a stress tensor and a
surface operator of general shape cannot be constructed only from local
geometric data depending only on the shape of the surface. We verify this
holographically at d=3 for Wilson line operators or equivalently the twist
operator corresponding to computing the entanglement entropy using the
Ryu-Takayanagi formula. We discuss possible implications of this result.Comment: 20 pages, no figur
Demonstration of Deutsch's Algorithm on a Stable Linear-Optical Quantum Computer
We report an experimental demonstration of quantum Deutsch's algorithm by
using linear-optical system. By employing photon's polarization and spatial
modes, we implement all balanced and constant functions for quantum computer.
The experimental system is very stable and the experimental data are excellent
in accordance with the theoretical results.Comment: 7 pages, 4 figure
The GRB-Supernova Connection
Long-duration gamma-ray bursts (GRBs) are believed to be produced by the core
collapse of massive stars and hence to be connected with supernovae (SNe).
Indeed, for four pairs of GRBs and SNe, spectroscopically confirmed connection
has been firmly established. For more than a dozen of GRBs the SN signature
(the `red bump') has been detected in the afterglow lightcurves. Based on the
four pairs of GRBs and SNe with spectroscopically confirmed connection a tight
correlation was found between the peak spectral energy of GRBs and the peak
bolometric luminosity of the underlying SNe. The recent discovery of X-ray
flash 080109 associated with a normal core-collapse SN 2008D confirmed this
relation and extended the GRB-SN connection. Progress on the GRB-SN connection
is briefly reviewed.Comment: 6 pages, 5 figures. To appear in the proceedings of "2008 Nanjing GRB
conference", Nanjing, 23-27 June 200
How to Train Your Dragon: Tamed Warping Network for Semantic Video Segmentation
Real-time semantic segmentation on high-resolution videos is challenging due
to the strict requirements of speed. Recent approaches have utilized the
inter-frame continuity to reduce redundant computation by warping the feature
maps across adjacent frames, greatly speeding up the inference phase. However,
their accuracy drops significantly owing to the imprecise motion estimation and
error accumulation. In this paper, we propose to introduce a simple and
effective correction stage right after the warping stage to form a framework
named Tamed Warping Network (TWNet), aiming to improve the accuracy and
robustness of warping-based models. The experimental results on the Cityscapes
dataset show that with the correction, the accuracy (mIoU) significantly
increases from 67.3% to 71.6%, and the speed edges down from 65.5 FPS to 61.8
FPS. For non-rigid categories such as "human" and "object", the improvements of
IoU are even higher than 18 percentage points
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