12,403 research outputs found
The Maxwell-Bloch Theory in Quantum Optics and the Kondo Model
In this letter, the problem of radiation in a fiber geometry interacting with
a two level atom is mapped onto the anisotropic Kondo model. Thermodynamical
and dynamical properties are then computed exploiting the integrability of this
latter system. We compute some correlation functions, decay rates and Lamb
shifts. In turn this leads to an analysis of the classical limit of the
anisotropic Kondo model.Comment: 4 pages, 1 figure. In Latex. Uses Revte
A comment on finite temperature correlations in integrable QFT
I discuss and extend the recent proposal of Leclair and Mussardo for finite
temperature correlation functions in integrable QFTs. I give further
justification for its validity in the case of one point functions of conserved
quantities. I also argue that the proposal is not correct for two (and higher)
point functions, and give some counterexamples to justify that claim.Comment: 11 page
Neo-liberalism at a time of crisis: the case of taxation
This essay explores how the global financial crisis of 2008–2009 has affected the stability of what Stephen Gill has termed the ‘new constitutionalism of disciplinary neo-liberalism’, more precisely, in the realm of international tax policy. Rather than providing an in-depth and complete empirical study of the matter, this essay will highlight certain interesting developments and touch upon a series of possibly relevant questions that could form the basis for a future research agenda. In the first section, we will examine the remarkable strength and resilience of the new constitutionalism as the institutional component of neo-liberal hegemony. Then we will proceed to an exploration of the impact of the crisis on this hegemony, also paying attention to deepening geopolitical multipolarity as an additional variable. The final, more empirical section will investigate the case of international taxation in this context, and demonstrate that new constitutionalism remains a crucial supporting pillar of neo-liberal globalisation
Conditional inference with a complex sampling: exact computations and Monte Carlo estimations
In survey statistics, the usual technique for estimating a population total
consists in summing appropriately weighted variable values for the units in the
sample. Different weighting systems exit: sampling weights, GREG weights or
calibration weights for example. In this article, we propose to use the inverse
of conditional inclusion probabilities as weighting system. We study examples
where an auxiliary information enables to perform an a posteriori
stratification of the population. We show that, in these cases, exact
computations of the conditional weights are possible. When the auxiliary
information consists in the knowledge of a quantitative variable for all the
units of the population, then we show that the conditional weights can be
estimated via Monte-Carlo simulations. This method is applied to outlier and
strata-Jumper adjustments
Discussion: Applications and Innovations in Spatial Econometrics
These articles provide a discussion of studies presented in a session on spatial econometrics, focusing on the ability of spatial regression models to quantify the magnitude of spatial spillover impacts. Both articles presented argue that a proper modeling of spatial spillovers is required to truly understand the phenomena under study, in one case the impact of climate change on land values (or crop yields) and in the second the role of regional industry composition on regional business establishment growth.lagged variables, panel data, spatial spillovers, Community/Rural/Urban Development, Environmental Economics and Policy, Resource /Energy Economics and Policy, C33, C51,
- …