17,953 research outputs found
The Network Picture of Labor Flow
We construct a data-driven model of flows in graphs that captures the
essential elements of the movement of workers between jobs in the companies
(firms) of entire economic systems such as countries. The model is based on the
observation that certain job transitions between firms are often repeated over
time, showing persistent behavior, and suggesting the construction of static
graphs to act as the scaffolding for job mobility. Individuals in the job
market (the workforce) are modelled by a discrete-time random walk on graphs,
where each individual at a node can possess two states: employed or unemployed,
and the rates of becoming unemployed and of finding a new job are node
dependent parameters. We calculate the steady state solution of the model and
compare it to extensive micro-datasets for Mexico and Finland, comprised of
hundreds of thousands of firms and individuals. We find that our model
possesses the correct behavior for the numbers of employed and unemployed
individuals in these countries down to the level of individual firms. Our
framework opens the door to a new approach to the analysis of labor mobility at
high resolution, with the tantalizing potential for the development of full
forecasting methods in the future.Comment: 27 pages, 6 figure
Dynamics and thermalization of Bose-Einstein condensate in Sinai oscillator trap
We study numerically the evolution of Bose-Einstein condensate in the Sinai
oscillator trap described by the Gross-Pitaevskii equation in two dimensions.
In the absence of interactions this trap mimics the properties of Sinai
billiards where the classical dynamics is chaotic and the quantum evolution is
described by generic properties of quantum chaos and random matrix theory. We
show that, above a certain border, the nonlinear interactions between atoms
lead to the emergence of dynamical thermalization which generates the
statistical Bose-Einstein distribution over eigenmodes of the system without
interactions. Below the thermalization border the evolution remains
quasi-integrable. Such a Sinai oscillator trap, formed by the oscillator
potential and a repulsive disk located in the vicinity of the center, had been
already realized in rst experiments with the Bose-Einstein condensate formation
by Ketterle group in 1995 and we argue that it can form a convenient test bed
for experimental investigations of dynamical of thermalization. Possible links
and implications for Kolmogorov turbulence in absence of noise are also
discussed.Comment: 11 pages, 14 figures. Final version. Accepted forpublication at Phys.
Rev. A. Additional information available at
http://www.quantware.ups-tlse.fr/QWLIB/sinaioscillator
- …