12,273 research outputs found
Asymptotic behavior of the solution of the space dependent variable order fractional diffusion equation: ultra-slow anomalous aggregation
We find for the first time the asymptotic representation of the solution to
the space dependent variable order fractional diffusion and Fokker-Planck
equations. We identify a new advection term that causes ultra-slow spatial
aggregation of subdiffusive particles due to dominance over the standard
advection and diffusion terms, in the long-time limit. This uncovers the
anomalous mechanism by which non-uniform distributions can occur. We perform
experiments on intracellular lysosomal distributions and Monte Carlo
simulations and find excellent agreement between the asymptotic solution,
particle histograms and experiments.Comment: 6 page
What are Best Practices to Define a Common Understanding of What is Expected of Companies\u27 Leaders, and How is this Understanding Structured?
[Excerpt] Today, companies need to have strong and meaningful leadership drive their business. A critical component of strong leadership involves identifying the competencies and behaviors that enable leaders to succeed. This is primarily accomplished by implementing a leadership competency model (LCM), which has benefits but is often ineffectively utilized. Knowing which leadership competencies are key for global companies and how companies are implementing LCMs is critical for success in developing strong effective leaders to influence their teams and the overall business
Quasineutral limit for Vlasov-Poisson with Penrose stable data
We study the quasineutral limit of a Vlasov-Poisson system that describes the
dynamics of ions in a plasma. We handle data with Sobolev regularity under the
sharp assumption that the profile of the initial data in the velocity variable
satisfies a Penrose stability condition.
As a by-product of our analysis, we obtain a well-posedness theory for the
limit equation (which is a Vlasov equation with Dirac distribution as
interaction kernel) for such data
Geometric analysis of the linear Boltzmann equation I. Trend to equilibrium
This work is devoted to the analysis of the linear Boltzmann equation in a
bounded domain, in the presence of a force deriving from a potential. The
collision operator is allowed to be degenerate in the following two senses: (1)
the associated collision kernel may vanish in a large subset of the phase
space; (2) we do not assume that it is bounded below by a Maxwellian at
infinity in velocity. We study how the association of transport and collision
phenomena can lead to convergence to equilibrium, using concepts and ideas from
control theory. We prove two main classes of results. On the one hand, we show
that convergence towards an equilibrium is equivalent to an almost everywhere
geometric control condition. The equilibria (which are not necessarily
Maxwellians with our general assumptions on the collision kernel) are described
in terms of the equivalence classes of an appropriate equivalence relation. On
the other hand, we characterize the exponential convergence to equilibrium in
terms of the Lebeau constant, which involves some averages of the collision
frequency along the flow of the transport. We handle several cases of phase
spaces, including those associated to specular reflection in a bounded domain,
or to a compact Riemannian manifold
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