scholarly journals Entanglement wedge cross section in holographic excited states

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Mohammad Sahraei ◽  
Mohammad Javad Vasli ◽  
M. Reza Mohammadi Mozaffar ◽  
Komeil Babaei Velni
Keyword(s):  
Mutual Information ◽  
Excited States ◽  
Cross Section ◽  
Generic Properties ◽  
Information Measures ◽  
Logarithmic Negativity ◽  
Symmetric Configuration ◽  
Boundary Information ◽  
Correlation Measures ◽  
Matter Fields

Abstract We evaluate the entanglement wedge cross section (EWCS) in asymptotically AdS geometries which are dual to boundary excited states. We carry out a perturbative analysis for calculating EWCS between the vacuum and other states for a symmetric configuration consisting of two disjoint strips and obtain analytical results in the specific regimes of the parameter space. In particular, when the states described by purely gravitational excitations in the bulk we find that the leading correction to EWCS is negative and hence the correlation between the boundary subregions decreases. We also study other types of excitations upon adding the extra matter fields including current and scalar condensate. Our study reveals some generic properties of boundary information measures dual to EWCS, e.g., entanglement of purification, logarithmic negativity and reflected entropy. Finally, we discuss how these results are consistent with the behavior of other correlation measures including the holographic mutual information.

scholarly journals Evolution of entanglement wedge cross section following a global quench

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Komeil Babaei Velni ◽  
M. Reza Mohammadi Mozaffar ◽  
M.H. Vahidinia
Keyword(s):  
Cross Section ◽  
Linear Growth ◽  
Early Time ◽  
Quadratic Growth ◽  
Late Time ◽  
Zero Temperature ◽  
Information Measures ◽  
Logarithmic Negativity ◽  
Linear Behavior ◽  
Logarithmic Growth

Abstract We study the evolution of entanglement wedge cross section (EWCS) in the Vaidya geometry describing a thin shell of null matter collapsing into the AdS vacuum to form a black brane. In the holographic context, it is proposed that this quantity is dual to different information measures including entanglement of purification, reflected entropy, odd entropy and logarithmic negativity. In 2 + 1 dimensions, we present a combination of numerical and analytic results on the evolution and scaling of EWCS for strip shaped boundary subregions after a thermal quench. In the limit of large subregions, we find that the time evolution of EWCS is characterized by three different scaling regimes: an early time quadratic growth, an intermediate linear growth and a late time saturation. Further, in 3 + 1 dimensions, we examine the scaling behavior by considering thermal and electromagnetic quenches. In the case of a thermal quench, our numerical analysis supply results similar to observations made for the lower dimension. On the other hand, for electromagnetic quenches at zero temperature, an interesting feature is a departure from the linear behavior of the evolution to logarithmic growth.

scholarly journals 0+ States of 8Be

1968 ◽  
Vol 21 (3) ◽  
pp. 239 ◽  
Author(s):  
FC Barker ◽  
HJ Hay ◽  
PB Treacy
Keyword(s):  
Excited State ◽  
Excited States ◽  
Cross Section ◽  
Scattering Data ◽  
Excitation Energies ◽  
R Matrix ◽  
Channel Radius

The light even nuclei with A ;;;. 10 have 0+ excited states near 6 MeV, probably with large (X-particle reduced widths. A similar state in BBe would be very broad. Evidence for 0+ excited states in BBe has been obtained here using many-level R-matrix fits to known (X-(X scattering data, but the excitation energies depend strongly on the assumed channel radius. For a simultaneous fit to the 9Be(p, d)BBe cross section, assuming these higher states are not strongly populated, the channel radius is restricted to (7~~) fm, implying a 0+ excited state at (6=f3) MeV of width (9=f4) MeV.

Information Measures

2015 ◽  
pp. 129-142
Keyword(s):  
Information Theory ◽  
Mutual Information ◽  
Order Logic ◽  
Unified Framework ◽  
Higher Order Logic ◽  
Absolutely Continuous ◽  
Information Measures ◽  
Finite Spaces ◽  
Nikodym Derivative ◽  
Lebesgue Integration

This chapter presents a higher-order-logic formalization of the main concepts of information theory (Cover & Thomas, 1991), such as the Shannon entropy and mutual information, using the formalization of the foundational theories of measure, Lebesgue integration, and probability. The main results of the chapter include the formalizations of the Radon-Nikodym derivative and the Kullback-Leibler (KL) divergence (Coble, 2010). The latter provides a unified framework based on which most of the commonly used measures of information can be defined. The chapter then provides the general definitions that are valid for both discrete and continuous cases and then proves the corresponding reduced expressions where the measures considered are absolutely continuous over finite spaces.

EEG TRANSFER ENTROPY TRACKS CHANGES IN INFORMATION TRANSFER ON THE ONSET OF VISION

2012 ◽  
Vol 17 ◽  
pp. 9-18 ◽  
Author(s):  
M. D. MADULARA ◽  
P. A. B. FRANCISCO ◽  
S. NAWANG ◽  
D. C. AROGANCIA ◽  
C. J. CELLUCCI ◽  
...  
Keyword(s):  
Mutual Information ◽  
Information Transfer ◽  
Occipital Lobe ◽  
Transfer Entropy ◽  
The Other ◽  
Information Measures ◽  
Eyes Closed ◽  
Eyes Open ◽  
Almost All ◽  
Nonlinear Correlations

We investigate the pairwise mutual information and transfer entropy of ten-channel, free-running electroencephalographs measured from thirteen subjects under two behavioral conditions: eyes open resting and eyes closed resting. Mutual information measures nonlinear correlations; transfer entropy determines the directionality of information transfer. For all channel pairs, mutual information is generally lower with eyes open compared to eyes closed indicating that EEG signals at different scalp sites become more dissimilar as the visual system is engaged. On the other hand, transfer entropy increases on average by almost two-fold when the eyes are opened. The largest one-way transfer entropies are to and from the Oz site consistent with the involvement of the occipital lobe in vision. The largest net transfer entropies are from F3 and F4 to almost all the other scalp sites.

Low overlap image registration based on both entropy and mutual information measures

OCEANS 2008 ◽  
2008 ◽  
Author(s):  
Cedric de Cesare ◽  
Maria-Joao Rendas ◽  
Anne-Gaelle Allais ◽  
Michel Perrier
Keyword(s):  
Image Registration ◽  
Mutual Information ◽  
Information Measures

Photoneutron Cross Sections in 14N

1972 ◽  
Vol 50 (15) ◽  
pp. 1689-1696 ◽  
Author(s):  
R. W. Gellie ◽  
K. H. Lokan ◽  
N. K. Sherman ◽  
R. G. Johnson ◽  
J. I. Lodge
Keyword(s):  
Excited States ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Emission ◽  
Giant Resonance ◽  
Sequential Decay ◽  
Dipole Resonance ◽  
Intermediate States ◽  
Integrated Cross Section ◽  
High Degree

Photoneutron distributions from 14N have been obtained by time-of-flight methods, for bremsstrahlung end-point energies increasing in 2 MeV steps from 15.5 to 29.5 MeV. A large part of the neutron yield is associated with the sequential decay of 14N to 12C, through well-defined intermediate states of 13C, at 7.55, 8.86, and 11.80 MeV, which are unstable against neutron emission. The (γ,n0) cross section for neutron emission to the ground state of 13N is found to agree very closely with the corresponding (γ,p0) cross section, implying a high degree of isospin purity for the giant dipole resonance of 14N. It is observed that the decay of the giant resonance proceeds freely through those odd-parity excited states of the A = 13 nuclei which are single hole states formed by the removal of a p-shell nucleon from the parent 14N.The integrated cross section for all neutron-producing interactions is found to be 88 ± 5 MeV mb.

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