13,803 research outputs found
An Almost-Sure CLT for Stretched Polymers
We prove an almost sure CLT for spatial extension of stretched (meaning
subject to a non-zero pulling force) polymers at very weak disorder in all
dimensions d+1 larger than or equal to 4.Comment: Final version. To be published in the Electronic Journal of
Probabilit
Localization and delocalization of random interfaces
The probabilistic study of effective interface models has been quite active
in recent years, with a particular emphasis on the effect of various external
potentials (wall, pinning potential, ...) leading to
localization/delocalization transitions. I review some of the results that have
been obtained. In particular, I discuss pinning by a local potential, entropic
repulsion and the (pre)wetting transition, both for models with continuous and
discrete heights.Comment: Published at http://dx.doi.org/10.1214/154957806000000050 in the
Probability Surveys (http://www.i-journals.org/ps/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Entropic repulsion of an interface in an external field
We consider an interface above an attractive hard wall in the complete
wetting regime, and submitted to the action of an external increasing, convex
potential, and study its delocalization as the intensity of this potential
vanishes. Our main motivation is the analysis of critical prewetting, which
corresponds to the choice of a linear external potential.
We also present partial results on critical prewetting in the two dimensional
Ising model, as well as a few (weak) results on pathwise estimates for the pure
wetting problem for effective interface models
How Do Ethnic Militias Perpetuate in Nigeria? A Micro-level Perspective on the Oodua People’s Congress
The paper discusses the recently promoted view that organized insurgent violence should either be conducted by activists bonded together by social capital ties or self-interested quasi-mercenaries, depending on the type of financial resources available to the group. We contrast this perspective with the study of an ethnic Nigerian militia, the Oodua People’s Congress (OPC). It appears that the success of this militia over time was jointly sustained by important preexisting social connections and numerous opportunities for economic gains. The perpetuation of OPC, we argue, is ensured by a ‘moral economy’ whose members enjoy selfinsurance in an environment perceived as unsafe.Militias, Violent Mobilization, Extra-legal Governance, Security, Africa, Nigeria
Chronic Rigidity: The East's Labour Market Problem and How to Fix It
Canada’s generally good labour market performance over the past several years, exemplified in a 33-year, record-low unemployment rate, masks strikingly large regional disparities. In September 2007, the national unemployment rate was 6 percent, but it ranged from 2.8 percent in central Alberta to 17.8 percent in southern Newfoundland and Labrador. Such wide variances are also present within single provinces, from 5.4 percent to 12 percent in New Brunswick, for example, in that same month. These statistics suggest rigidity in Canada’s labour market. The economy creates jobs at a rapid pace, but people do not readily move to where the jobs are, leaving large pockets of unemployment. And hence our economy as a whole does not achieve its full economic potential.social policy, labour market performance, unemployment rates
Self-Attractive Random Walks: The Case of Critical Drifts
Self-attractive random walks undergo a phase transition in terms of the
applied drift: If the drift is strong enough, then the walk is ballistic,
whereas in the case of small drifts self-attraction wins and the walk is
sub-ballistic. We show that, in any dimension at least 2, this transition is of
first order. In fact, we prove that the walk is already ballistic at critical
drifts, and establish the corresponding LLN and CLT.Comment: Final version sent to the publisher. To appear in Communications in
Mathematical Physic
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