6,897 research outputs found
Explicit reconstruction of the entanglement wedge
The problem of how the boundary encodes the bulk in AdS/CFT is still a
subject of study today. One of the major issues that needs more elucidation is
the problem of subregion duality; what information of the bulk a given boundary
subregion encodes. Although the proof given by Dong, Harlow, and Wall states
that the entanglement wedge of the bulk should be encoded in boundary
subregions, no explicit procedure for reconstructing the entanglement wedge was
given so far. In this paper, mode sum approach to obtaining smearing functions
for a single bulk scalar is generalised to include bulk reconstruction in the
entanglement wedge of boundary subregions. It is generally expectated that
solutions to the wave equation on a complicated coordinate patch are needed,
but this hard problem has been transferred to a less hard but tractable problem
of matrix inversion.Comment: version accepted by JHEP; added references and discussions on
covarianc
Statistical properties of chaotic microcavities in small and large opening cases
We study the crossover behavior of statistical properties of eigenvalues in a
chaotic microcavity with different refractive indices. The level spacing
distributions change from Wigner to Poisson distributions as the refractive
index of a microcavity decreases. We propose a non-hermitian matrix model with
random elements describing the spectral properties of the chaotic microcavity,
which exhibits the crossover behaviors as the opening strength increases.Comment: 22 pages, 6 figure
Quantum corrections to frame-dragging in scattering amplitudes
Frame-dragging effect manifests itself as polarization direction rotation
when linearly polarized electromagnetic/gravitational wave scatters from a
spinning point source through gravitational interactions. Treating general
relativity as an effective field theory, the polarization rotation angle and
its quantum corrections are computed using scattering amplitudes. While the
classical angle is universal as expected from the equivalence principle, the
quantum corrections are found to be different between electromagnetic and
gravitational waves, supporting earlier studies that some formulations of the
equivalence principle seem to be violated in the quantum regime.Comment: more accessible discussions, shortened abstract, updated references;
7 pages, 1 TikZ figure, 1 ancillary fil
Quasiattractors in coupled maps and coupled dielectric cavities
We study the origin of attracting phenomena in the ray dynamics of coupled
optical microcavities. To this end we investigate a combined map that is
composed of standard and linear map, and a selection rule that defines when
which map has to be used. We find that this system shows attracting dynamics,
leading exactly to a quasiattractor, due to collapse of phase space. For
coupled dielectric disks, we derive the corresponding mapping based on a ray
model with deterministic selection rule and study the quasiattractor obtained
from it. We also discuss a generalized Poincar\'e surface of section at
dielectric interfaces.Comment: 7 pages, 7 figure
Heterogeneous Investors and their Changing Demand and Supply Schedules for Individual Common Stocks
Using 550 million limit orders submitted in the Korea Stock Exchange, we estimate demand and supply elasticities of heterogeneous investor types and their changes around the Asian financial crisis. We find that domestic individuals have substantially more inelastic demand and supply curves than domestic institutions and foreign investors. The crisis permanently reduced price elasticities of domestic individuals by 50% but had no effect on those of foreign investors. Institutional changes restricting margin purchases, implemented after the crisis, seem particularly important in explaining the dramatic drop. Information heterogeneity, availability of close substitutes and arbitrage risk also explain time-series variations in elasticities.
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