On the RKKY range function of a one dimensional non interacting electron gas

We show that the pitfalls encountered in earlier calculations of the RKKY range function for a non interacting one dimensional electron gas at zero temperature can be unraveled and successfully dealt with through a proper handling of the impurity potential.Comment: to appear in Phys. Re

The gender dimension of outsiderness in Western Europe: a comparative cross-model analysis

Purpose – The article investigates whether and to what extent outsiderness is gendered in Western Europe, both in terms of its spread and degree. It thus explores which male and female post-Fordist social classes are more exposed to the risk of this phenomenon. It also scrutinizes whether such a gendered characterization has varied over time and across clusters of Western European countries. Design/methodology/approach – Relying on a comparative analysis of the data provided by the European Social Survey (ESS) dataset and comparing two points in time – the early/mid-2000s and the late 2010s – the work provides both a dichotomous and continuous variable of outsiderness, which measure its spread and degree in the female and male workforces of a pooled set of growth models. Findings – The empirical analysis shows that outsiderness is profoundly gendered in Western Europe and thus a feminized social phenomenon. However, the comparative investigation highlights that outsiderness has been genderized in diverse ways across the four growth models. Different patterns of gendered outsiderness can be identified. Originality/value – The article provides a comparative and diachronic analysis of outsiderness from a gender lens, putting into a mutual dialogue different literature on labour market, and shows that outsiderness represents a key analytical dimension for assessing gender inequalities

Electronic viscosity in a quantum well: A test for the local density approximation

In the local density approximation (LDA) for electronic time-dependent current-density functional theory (TDCDFT) many-body effects are described in terms of the visco-elastic constants of the homogeneous three-dimensional electron gas. In this paper we critically examine the applicability of the three-dimensional LDA to the calculation of the viscous damping of 1-dimensional collective oscillations of angular frequency $\omega$ in a quasi 2-dimensional quantum well. We calculate the effective viscosity $\zeta(\omega)$ from perturbation theory in the screened Coulomb interaction and compare it with the commonly used three-dimensional LDA viscosity $Y(\omega)$. Significant differences are found. At low frequency $Y(\omega)$ is dominated by a shear term, which is absent in $\zeta(\omega)$. At high frequency $\zeta(\omega)$ and $Y(\omega)$ exhibit different power law behaviors ($\omega^{-3}$ and $\omega^{-5/2}$ respectively), reflecting different spectral densities of electron-hole excitations in two and three dimensions. These findings demonstrate the need for better approximations for the exchange-correlation stress tensor in specific systems where the use of the three-dimensional functionals may lead to unphysical results.Comment: 10 pages, 7 figures, RevTex

Pseudospin Magnetism in Graphene

We predict that neutral graphene bilayers are pseudospin magnets in which the charge density-contribution from each valley and spin spontaneously shifts to one of the two layers. The band structure of this system is characterized by a momentum-space vortex which is responsible for unusual competition between band and kinetic energies leading to symmetry breaking in the vortex core. We discuss the possibility of realizing a pseudospin version of ferromagnetic metal spintronics in graphene bilayers based on hysteresis associated with this broken symmetry.Comment: 5 pages, 4 figures; added figure 1, modified introduction and discussion; updated reference

The makers get it all? The coalitional welfare politics of Populist Radical Right Parties in Europe. The case studies of Austria and Italy

The article investigates whether and to what extent the welfare policies of Populist Radical Right Parties (PRRPs) vary in diverse government coalitions. Relying on a multidimensional framework differentiating coalitional politics along the welfare size and deservingness dimension, we conduct a comparative case study analysing welfare reforms of the ‘standard’ centre-right/PRRP government coalition ÖVP-FPÖ in Austria and the ‘new’ populist government coalition M5S-Lega in Italy. We find that both PRRPs do not promote pro-welfare policies in general, but rather opt for selective expansion of benefits for ‘mak- ers’, while aiming at retrenching benefits for ‘takers’. This welfare strategy includes pensioners and male breadwinner families but excludes migrants or long-term unemployed. The analysis furthermore shows that the central line of conflict with the centre-right ÖVP is mostly about the size of welfare policies, espe- cially for ‘deserving’ citizens, while with the socially more left-leaning M5S it is rather centred around the deservingness dimension, e.g., benefits for takers. These results offer a more fine-grained understanding of the PRRPs’ welfare agenda and their coalitional welfare politics in office

Italy and Spain at a crossroads: the politics of active social policies in southern Europe under a gender perspective

Purpose – The article explores to what extent party politics has influenced the different trajectories in Spain and Italy in terms of gendered active social policies (ASPs) (i.e. ALMPs and WLBPs). Second, it investigates how social and political modernization in the two countries has facilitated or hindered party competition on gendered ASPs. Design/methodology/approach – To investigate to what extent parties support gendered ASPs, the article relies on an original content analysis of party manifestos issued during the 2010s national elections. A total of 1387 quasi-sentences have been coded. The results were then quantified to graphically show how positions differentiate across parties and countries. Findings – The content analysis of party manifestos displays that party politics matters: gendered ASPs are backed in a very different way by the Spanish and Italian parties. While in Spain all political parties have strongly championed ALMPs and WLBPs, this is not the case for the Italian parties. The research has also stressed that the specific path of social and political modernization is an important intervening variable that alters positively or negatively parties’ support for gendered ASPs. Originality/value – The article contributes to widen theoretically and empirically the literature on ASPs in the Southern European countries. Theoretically, it questions the supposed homogeneity of the Southern social model and investigated the alleged bifurcation between Italy and Spain, focusing on those policies – ASPs – that constitute the foundations of the Southern model: familialism and dualization. Furthermore, this bifurcation was analyzed adopting a gender perspective, and exploring adherence to or departure from the Southern model. Third, the article focuses on the politics of ASPs demonstrating that inspecting the political arena can contribute to explain policy change

On the "Causality Paradox" of Time-Dependent Density Functional Theory

I show that the so-called causality paradox of time-dependent density functional theory arises from an incorrect formulation of the variational principle for the time evolution of the density. The correct formulation not only resolves the paradox in real time, but also leads to a new expression for the causal exchange-correlation kernel in terms of Berry curvature. Furthermore, I show that all the results that were previously derived from symmetries of the action functional remain valid in the present formulation. Finally, I develop a model functional theory which explicitly demonstrates the workings of the new formulation.Comment: 21 page

Resonances within Chaos

A chaotic system under periodic forcing can develop a periodically visited strange attractor. We discuss simple models in which the phenomenon, quite easy to see in numerical simulations, can be completely studied analytically.Comment: 12 pages, 3 figure

On the feasibility of collaborative green data center ecosystems

The increasing awareness of the impact of the IT sector on the environment, together with economic factors, have fueled many research efforts to reduce the energy expenditure of data centers. Recent work proposes to achieve additional energy savings by exploiting, in concert with customers, service workloads and to reduce data centers’ carbon footprints by adopting demand-response mechanisms between data centers and their energy providers. In this paper, we debate about the incentives that customers and data centers can have to adopt such measures and propose a new service type and pricing scheme that is economically attractive and technically realizable. Simulation results based on real measurements confirm that our scheme can achieve additional energy savings while preserving service performance and the interests of data centers and customers.Peer ReviewedPostprint (author's final draft