2,258 research outputs found
Symmetry in Full Counting Statistics, Fluctuation Theorem, and Relations among Nonlinear Transport Coefficients in the Presence of a Magnetic Field
We study full counting statistics of coherent electron transport through
multi-terminal interacting quantum-dots under a finite magnetic field.
Microscopic reversibility leads to the symmetry of the cumulant generating
function, which generalizes the fluctuation theorem in the context of quantum
transport. Using this symmetry, we derive the Onsager-Casimir relation in the
linear transport regime and universal relations among nonlinear transport
coefficients.Comment: 4.1pages, 1 figur
Fluctuation theorem for currents in open quantum systems
A quantum-mechanical framework is set up to describe the full counting
statistics of particles flowing between reservoirs in an open system under
time-dependent driving. A symmetry relation is obtained which is the
consequence of microreversibility for the probability of the nonequilibrium
work and the transfer of particles and energy between the reservoirs. In some
appropriate long-time limit, the symmetry relation leads to a steady-state
quantum fluctuation theorem for the currents between the reservoirs. On this
basis, relationships are deduced which extend the Onsager-Casimir reciprocity
relations to the nonlinear response coefficients.Comment: 19 page
Thermodynamic time asymmetry in nonequilibrium fluctuations
We here present the complete analysis of experiments on driven Brownian
motion and electric noise in a circuit, showing that thermodynamic entropy
production can be related to the breaking of time-reversal symmetry in the
statistical description of these nonequilibrium systems. The symmetry breaking
can be expressed in terms of dynamical entropies per unit time, one for the
forward process and the other for the time-reversed process. These entropies
per unit time characterize dynamical randomness, i.e., temporal disorder, in
time series of the nonequilibrium fluctuations. Their difference gives the
well-known thermodynamic entropy production, which thus finds its origin in the
time asymmetry of dynamical randomness, alias temporal disorder, in systems
driven out of equilibrium.Comment: to be published in : Journal of Statistical Mechanics: theory and
experimen
Thermodynamic large fluctuations from uniformized dynamics
Large fluctuations have received considerable attention as they encode
information on the fine-scale dynamics. Large deviation relations known as
fluctuation theorems also capture crucial nonequilibrium thermodynamical
properties. Here we report that, using the technique of uniformization, the
thermodynamic large deviation functions of continuous-time Markov processes can
be obtained from Markov chains evolving in discrete time. This formulation
offers new theoretical and numerical approaches to explore large deviation
properties. In particular, the time evolution of autonomous and non-autonomous
processes can be expressed in terms of a single Poisson rate. In this way the
uniformization procedure leads to a simple and efficient way to simulate
stochastic trajectories that reproduce the exact fluxes statistics. We
illustrate the formalism for the current fluctuations in a stochastic pump
model
To adapt or not to adapt? Technical debt and learning driven self-adaptation for managing runtime performance
Self-adaptive system (SAS) can adapt itself to optimize various key performance indicators in response to the dynamics and uncertainty in environment. In this paper, we present Debt Learning Driven Adaptation (DLDA), an framework that dynamically determines when and whether to adapt the SAS at runtime. DLDA leverages the temporal adaptation debt, a notion derived from the technical debt metaphor, to quantify the time-varying money that the SAS carries in relation to its performance and Service Level Agreements. We designed a temporal net debt driven labeling to label whether it is economically healthier to adapt the SAS (or not) in a circumstance, based on which an online machine learning classifier learns the correlation, and then predicts whether to adapt under the future circumstances. We conducted comprehensive experiments to evaluate DLDA with two different planners, using 5 online machine learning classifiers, and in comparison to 4 state-of-the-art debt- oblivious triggering approaches. The results reveal the effectiveness and superiority of DLDA according to different metrics
Fluctuation theorem for the effusion of an ideal gas
The probability distribution of the entropy production for the effusion of an
ideal gas between two compartments is calculated explicitly. The fluctuation
theorem is verified. The analytic results are in good agreement with numerical
data from hard disk molecular dynamics simulations.Comment: 11 pages, 10 figures, 2 table
Dynamical fluctuations for semi-Markov processes
We develop an Onsager-Machlup-type theory for nonequilibrium semi-Markov
processes. Our main result is an exact large time asymptotics for the joint
probability of the occupation times and the currents in the system,
establishing some generic large deviation structures. We discuss in detail how
the nonequilibrium driving and the non-exponential waiting time distribution
influence the occupation-current statistics. The violation of the Markov
condition is reflected in the emergence of a new type of nonlocality in the
fluctuations. Explicit solutions are obtained for some examples of driven
random walks on the ring.Comment: Minor changes, accepted for publication in Journal of Physics
Redundancy or GaAs? Two different approaches to solve the problem of SEU (Single Event Upset) in a digital optical link
Gab2 deficiency prevents Flt3-ITD driven acute myeloid leukemia in vivo
Internal tandem duplications (ITD) of the FMS-like tyrosine kinase 3 (FLT3) predict poor prognosis in acute myeloid leukemia (AML) and often co-exist with inactivating DNMT3A mutations. In vitro studies implicated Grb2-associated binder 2 (GAB2) as FLT3-ITD effector. Utilizing a Flt3-ITD knock-in, Dnmt3a haploinsufficient mouse model, we demonstrate that Gab2 is essential for the development of Flt3-ITD driven AML in vivo, as Gab2 deficient mice displayed prolonged survival, presented with attenuated liver and spleen pathology and reduced blast counts. Furthermore, leukemic bone marrow from Gab2 deficient mice exhibited reduced colony-forming unit capacity and increased FLT3 inhibitor sensitivity. Using transcriptomics, we identify the genes encoding for Axl and the Ret co-receptor Gfra2 as targets of the Flt3-ITD/Gab2/Stat5 axis. We propose a pathomechanism in which Gab2 increases signaling of these receptors by inducing their expression and by serving as downstream effector. Thereby, Gab2 promotes AML aggressiveness and drug resistance as it incorporates these receptor tyrosine kinases into the Flt3-ITD signaling network. Consequently, our data identify GAB2 as a promising biomarker and therapeutic target in human AML
Vortices in the two-dimensional Simple Exclusion Process
We show that the fluctuations of the partial current in two dimensional
diffusive systems are dominated by vortices leading to a different scaling from
the one predicted by the hydrodynamic large deviation theory. This is supported
by exact computations of the variance of partial current fluctuations for the
symmetric simple exclusion process on general graphs. On a two-dimensional
torus, our exact expressions are compared to the results of numerical
simulations. They confirm the logarithmic dependence on the system size of the
fluctuations of the partialflux. The impact of the vortices on the validity of
the fluctuation relation for partial currents is also discussed.Comment: Revised version to appear in Journal of Statistical Physics. Minor
correction
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