29,037 research outputs found
What Should We Learn From Early Hemodialysis Allocation About How We Should Be Using ECMO?
Early hemodialysis allocation deliberations should inform our current considerations of what constitutes reasonable uses of extracorporeal membrane oxygenation. Deliberative democracy can be used as a strategy to gather a plurality of views, consider criteria, and guide policy making
Dependence Estimation and Visualization in Multivariate Extremes with Applications to Financial Data
We investigate extreme dependence in a multivariate setting with special emphasis on financial applications. We introduce a new dependence function which allows us to capture the complete extreme dependence structure and present a nonparametric estimation procedure. The new dependence function is compared with existing measures including the spectral measure and other devices measuring extreme dependence. We also apply our method to a financial data set of zero coupon swap rates and estimate the extreme dependence in the data
Lindblad dynamics of the quantum spherical model
The purely relaxational non-equilibrium dynamics of the quantum spherical
model as described through a Lindblad equation is analysed. It is shown that
the phenomenological requirements of reproducing the exact quantum equilibrium
state as stationary solution and the associated classical Langevin equation in
the classical limit fix the form of the Lindblad dissipators, up to an
overall time-scale. In the semi-classical limit, the models' behaviour become
effectively the one of the classical analogue, with a dynamical exponent ,
and an effective temperature , renormalised by the quantum
coupling . A distinctive behaviour is found for a quantum quench, at zero
temperature, deep into the ordered phase , for dimensions.
Only for dimensions, a simple scaling behaviour holds true, with a
dynamical exponent , while for dimensions , logarithmic
corrections to scaling arise. The spin-spin correlator, the growing length
scale and the time-dependent susceptibility show the existence of several
logarithmically different length scales.Comment: 61 pages, 14 figure
Analysis of the conditional mutual information in ballistic and diffusive non-equilibrium steady-states
The conditional mutual information (CMI)
quantifies the amount of correlations shared between and \emph{given}
. It therefore functions as a more general quantifier of bipartite
correlations in multipartite scenarios, playing an important role in the theory
of quantum Markov chains. In this paper we carry out a detailed study on the
behavior of the CMI in non-equilibrium steady-states (NESS) of a quantum chain
placed between two baths at different temperatures. These results are used to
shed light on the mechanisms behind ballistic and diffusive transport regimes
and how they affect correlations between different parts of a chain. We carry
our study for the specific case of a 1D bosonic chain subject to local Lindblad
dissipators at the boundaries. In addition, the chain is also subject to
self-consistent reservoirs at each site, which are used to tune the transport
between ballistic and diffusive. As a result, we find that the CMI is
independent of the chain size in the ballistic regime, but decays
algebraically with in the diffusive case. Finally, we also show how this
scaling can be used to discuss the notion of local thermalization in
non-equilibrium steady-states
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