600 research outputs found
Injected Power Fluctuations in 1D Dissipative Systems
Using fermionic techniques, we compute exactly the large deviation function
(ldf) of the time-integrated injected power in several one-dimensional
dissipative systems of classical spins. The dynamics are T=0 Glauber dynamics
supplemented by an injection mechanism, which is taken as a Poissonian flipping
of one particular spin. We discuss the physical content of the results,
specifically the influence of the rate of the Poisson process on the properties
of the ldf.Comment: 18 pages, 8 figure
Persistence distributions for non gaussian markovian processes
We propose a systematic method to derive the asymptotic behaviour of the
persistence distribution, for a large class of stochastic processes described
by a general Fokker-Planck equation in one dimension. Theoretical predictions
are compared to simple solvable systems and to numerical calculations. The very
good agreement attests the validity of this approach.Comment: 7 pages, 1 figure, to be published in Europhysics Letter
Parametric phase transition in one dimension
We calculate analytically the phase boundary for a nonequilibrium phase
transition in a one-dimensional array of coupled, overdamped parametric
harmonic oscillators in the limit of strong and weak spatial coupling. Our
results show that the transition is reentrant with respect to the spatial
coupling in agreement with the prediction of the mean field theory.Comment: to appear in Europhysics letter
Critical Consciousness in Children and Adolescents: A Systematic Review,Critical Assessment, and Recommendations for Future Research
Critical consciousness refers to an individual’s awareness of oppressive systemic forces in society, a sense of efficacy to work against oppression, and engagement in individual or collective action against oppression. In the past few decades, interest in critical consciousness as a resource that may promote thriving in marginalized people has grown tremendously. This article critically examines the results of a systematic review of 67 studies of critical consciousness in children and adolescents, published between 1998 and 2019. Across these studies, major themes included the role of socialization experiences, relationships, and context in the development of critical consciousness. In addition, critical consciousness was associated with a number of adaptive developmental outcomes, including career-related, civic, social–emotional, and academic outcomes—especially for marginalized youth. However, our analysis highlights several critical gaps in the literature. We highlight the need for further delineation of the impacts of parent and peer socialization on critical consciousness in specific developmental periods and for studying critical consciousness at multiple levels of the ecological system. We further note the dearth of rigorous experimental or quasi-experimental studies in the area of interventions to promote critical consciousness. In addition, we note that developmental questions—questions about the nature and function of critical consciousness over time—are largely unanswered in the literature, including questions about how critical consciousness manifests and develops during childhood. Leveraging the findings of our systematic review, we outline key next steps for this rapidly growing area of research
Pseudo-boundaries in discontinuous 2-dimensional maps
It is known that Kolmogorov-Arnold-Moser boundaries appear in sufficiently
smooth 2-dimensional area-preserving maps. When such boundaries are destroyed,
they become pseudo-boundaries. We show that pseudo-boundaries can also be found
in discontinuous maps. The origin of these pseudo-boundaries are groups of
chains of islands which separate parts of the phase space and need to be
crossed in order to move between the different sub-spaces. Trajectories,
however, do not easily cross these chains, but tend to propagate along them.
This type of behavior is demonstrated using a ``generalized'' Fermi map.Comment: 4 pages, 4 figures, Revtex, epsf, submitted to Physical Review E (as
a brief report
Current large deviations in a driven dissipative model
We consider lattice gas diffusive dynamics with creation-annihilation in the
bulk and maintained out of equilibrium by two reservoirs at the boundaries.
This stochastic particle system can be viewed as a toy model for granular gases
where the energy is injected at the boundary and dissipated in the bulk. The
large deviation functional for the particle currents flowing through the system
is computed and some physical consequences are discussed: the mechanism for
local current fluctuations, dynamical phase transitions, the
fluctuation-relation
Different faces of the phantom
The SNe type Ia data admit that the Universe today may be dominated by some
exotic matter with negative pressure violating all energy conditions. Such
exotic matter is called {\it phantom matter} due to the anomalies connected
with violation of the energy conditions. If a phantom matter dominates the
matter content of the universe, it can develop a singularity in a finite future
proper time. Here we show that, under certain conditions, the evolution of
perturbations of this matter may lead to avoidance of this future singularity
(the Big Rip). At the same time, we show that local concentrations of a phantom
field may form, among other regular configurations, black holes with
asymptotically flat static regions, separated by an event horizon from an
expanding, singularity-free, asymptotically de Sitter universe.Comment: 6 pages, presented at IRGAC 2006, Barcelona, 11-15 July 200
High inclination orbits in the secular quadrupolar three-body problem
The Lidov-Kozai mechanism allows a body to periodically exchange its
eccentricity with inclination. It was first discussed in the framework of the
quadrupolar secular restricted three-body problem, where the massless particle
is the inner body, and later extended to the quadrupolar secular nonrestricted
three body problem. In this paper, we propose a different point of view on the
problem by looking first at the restricted problem where the massless particle
is the outer body. In this situation, equilibria at high mutual inclination
appear, which correspond to the population of stable particles that Verrier &
Evans (2008,2009) find in stable, high inclination circumbinary orbits around
one of the components of the quadruple star HD 98800. We provide a simple
analytical framework using a vectorial formalism for these situations. We also
look at the evolution of these high inclination equilibria in the non
restricted case.Comment: 11 pages, 6 figures. Accepted by MNRAS 2009 September 1
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