4,042 research outputs found
Reconstructing black hole exteriors and interiors using entanglement and complexity
Based on the AdS/CFT correspondence, we study how to reconstruct bulk
spacetime metrics by various quantum information measures on the boundary field
theories, which include entanglement entropy, mutual information, entanglement
of purification, and computational complexity according to the proposals of
complexity=volume 2.0 and complexity=generalized volume. We present several
reconstruction methods, all of which are free of UV divergence and most of
which are driven by the derivatives of the measures with respect to the
boundary scales. We illustrate that the exterior and interior of a black hole
can be reconstructed using the measures of spatial entanglement and
time-evolved complexity, respectively. We find that these measures always probe
the spacetime in a local way: reconstructing the bulk metric in different
radial positions requires the information at different boundary scales. We also
show that the reconstruction method using complexity=volume 2.0 proposal is the
simplest and has the strongest locality.Comment: 25 pages, 18 figures, 1 tabl
Multi-messenger observations of double neutron stars in Galactic disk with gravitational and radio waves
We evaluate the prospects for radio follow-up of the double neutron stars
(DNSs) in the Galactic disk that could be detected through future space-borne
gravitational wave (GW) detectors. We first simulate the DNS population in the
Galactic disk that is accessible to space-borne GW detectors according to the
merger rate from recent LIGO results. Using the inspiraling waveform for the
eccentric binary, the average number of the DNSs detectable by TianQin (TQ),
LISA, and TQ+LISA are 217, 368, and 429, respectively. For the joint GW
detection of TQ+LISA, the forecasted parameter estimation accuracies, based on
the Fisher information matrix, for the detectable sources can reach the levels
of , , , and . These estimation
accuracies are fitted in the form of power-law function of signal-to-noise
ratio. Next, we simulate the radio pulse emission from the possible pulsars in
these DNSs according to pulsar beam geometry and the empirical distributions of
spin period and luminosity. For the DNSs detectable by TQ+LISA, the average
number of DNSs detectable by the follow-up pulsar searches using the Parkes,
FAST, SKA1, and SKA are 8, 10, 43, and 87, respectively. Depending on the radio
telescope, the average distances of these GW-detectable pulsar binaries vary
from 1 to 7 kpc. Considering the dominant radiometer noise and phase jitter
noise, the timing accuracy of these GW-detectable pulsars can be as low as 70
while the most probable value is about 100 .Comment: 15 pages, 9 figures, 3 tables. To be published in PR
Evaluation of Ischemia-Modified Albumin and C-Reactive Protein in Type 2 Diabetics With and Without Ketosis
Adenoid cystic carcinoma of the esophagus: report of two cases and review of the Chinese literature
Squamous cell carcinoma is the major pathology type of esophageal cancer in China, where adenocarcinoma is rare and adenoid cystic carcinoma (ACC) is more rare comparing to the western countries. We report the surgical and pathologic findings of two cases of primary ACC of the esophagus, and review of the Chinese literature of this tumor. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/150758223884324
Nanotube ferroelectric tunnel junctions with giant tunneling electroresistance ratio
Low-dimensional ferroelectric tunnel junctions are appealing for the
realization of nanoscale nonvolatile memory devices due to their inherent
advantage of device miniaturization. Those based on current mechanisms still
have restrictions including low tunneling electroresistance (TER) effects and
complex heterostructures. Here, we introduce an entirely new TER mechanism to
construct the nanotube ferroelectric tunnel junction with ferroelectric
nanotubes as the tunneling region. When rolling a ferroelectric monolayer into
a nanotube, due to the coexistence of its intrinsic ferroelectric polarization
with the flexoelectric polarization induced by bending, there occurs
metal-insulator transition depending on radiative polarization states. For the
pristine monolayer, its out-of-plane polarization is tunable by an in-plane
electric field, the conducting states of the ferroelectric nanotube can thus be
tuned between metallic and insulating via axial electric means. Using
{\alpha}-In2Se3 as an example, our first-principles density functional theory
calculations and nonequilibrium Green's function formalism confirm the
feasibility of the TER mechanism and indicate an ultrahigh TER ratio exceeding
9.9*10^10% of the proposed nanotube ferroelectric tunnel junctions. Our
findings provide a promising approach based on simple homogeneous structures
for high density ferroelectric microelectronic devices with excellent ON/OFF
performance.Comment: 15 pages, 5 figure
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