Pion-pair formation and the pion dispersion relation in a hot pion gas

The possibility of pion--pair formation in a hot pion gas, based on the bosonic gap equation, is pointed out and discussed in detail. The critical temperature for condensation of pion pairs (Evans--Rashid transition) is determined as a function of the pion density. As for fermions, this phase transition is signaled by the appearance of a pole in the two--particle propagator. In bose systems there exists a second, lower critical temperature, associated with the appearance of the single--particle condensate. Between the two critical temperatures the pion dispersion relation changes from the usual quasiparticle dispersion to a Bogoliubov--like dispersion relation at low momenta. This generalizes the non-relativistic result for an attractive bose gas by Evans et al. Possible consequences for the inclusive pion spectra measured in heavy--ion collisions at ultra--relativistic energies are discussed.Comment: 16 pages revtex, 7 Postscript figure

In, Against and Beyond Precarity: Work in Insecure Times

In this Foreword to the special issue ‘In, Against and Beyond Precarity’ the guest editors take stock of the existing literature on precarity, highlighting the strengths and limitations of using this concept as an analytical tool for examining the world of work. Concluding that the overstretched nature of concept has diluted its political effectiveness, the editors suggest instead a focus on precarization as a process, drawing from perspectives that focus on the objective conditions, as well as subjective and heterogeneous experiences and perceptions of insecure employment. Framed in this way, they present a summary of the contributions to the special issue spanning a range of countries and organizational contexts, identifying key drivers, patterns and forms of precarization. These are conceptualized as implicit, explicit, productive and citizenship precarization. These forms and patterns indicate the need to address precariousness in the realm of social reproduction and post-wage politics, while holding these in tension with conflicts at the point of production. Finally, the guest editors argue for a dramatic re-think of current forms of state and non-state social protections as responses to the precarization of work and employment across countries in both the Global ‘North’ and ‘South’

Microscopic Treatment of Binary Interactions in the Non-Equilibrium Dynamics of Partially Bose-condensed Trapped Gases

In this paper we use microscopic arguments to derive a nonlinear Schr\"{o}dinger equation for trapped Bose-condensed gases. This is made possible by considering the equations of motion of various anomalous averages. The resulting equation explicitly includes the effect of repeated binary interactions (in particular ladders) between the atoms. Moreover, under the conditions that dressing of the intermediate states of a collision can be ignored, this equation is shown to reduce to the conventional Gross-Pitaevskii equation in the pseudopotential limit. Extending the treatment, we show first how the occupation of excited (bare particle) states affects the collisions, and thus obtain the many-body T-matrix approximation in a trap. In addition, we discuss how the bare particle many-body T-matrix gets dressed by mean fields due to condensed and excited atoms. We conclude that the most commonly used version of the Gross-Pitaevskii equation can only be put on a microscopic basis for a restrictive range of conditions. For partial condensation, we need to take account of interactions between condensed and excited atoms, which, in a consistent formulation, should also be expressed in terms of the many-body T-matrix. This can be achieved by considering fluctuations around the condensate mean field beyond those included in the conventional finite temperature mean field, i.e. Hartree-Fock-Bogoliubov (HFB), theory.Comment: Resolved some problems with printing of figure

Insertion as an alternative to workfare: active labour market schemes in the Parisian suburbs

Many governments have tightened the link between welfare and work by attaching conditionality to out-of-work benefits, extending these requirements to new client groups, and imposing market competition and greater managerial control in service delivery – principles typically characterised as ‘workfare’. Based on field research in Seine-Saint-Denis, we examine French ‘insertion’ schemes aimed at disadvantaged but potentially job-ready clients, characterized by weak conditionality, low marketization, strong professional autonomy, and local network control. We show that insertion systems have resisted policy attempts to expand workfare derived principles, reflecting street-level actors’ belief in the key advantages of the former over the latter. In contrast with arguments stressing institutional and cultural stickiness, our explanation for this resistance thus highlights the decentralized network governance of front-line services and the limits to central government power

Precarious education-to-work transitions: entering welfare professions under a workfarist regime

This article looks at the process of education-to-work transitions in female-dominated welfare professions within the Slovenian post-crisis context marked by a workfarist agenda. It departs from a scholarship that conceptualises precarity as a transitional vulnerability and disaffiliation exacerbated by workfarist policies to explore the contemporary experience of those trying to achieve professional integration under a volatile workfarist regime. The findings reveal a mismatch between established regulations for early career recruitment and professional licensing and the actual chances on the labour market to meet these requirements through available workfarist non-standard entry-level jobs/schemes designed for particular status and/or socio-demographic groups. It gives new evidence that European workfare regimes exacerbate precarity and a novel understanding of state-manufactured precarization as an intersectional process of marginalization and discrimination that not only hinders integration into welfare professions, but also downloads the costs of social reproduction on the next generation, causes precarious aging and widens intersectional differences

The state and class discipline: European labour market policy after the financial crisis

This paper looks at two related labour market policies that have persisted and even proliferated across Europe both before and after the financial crisis: wage restraint, and punitive workfare programmes. It asks why these policies, despite their weak empirical records, have been so durable. Moving beyond comparative-institutionalist explanations which emphasise institutional stickiness, it draws on Marxist and Kaleckian ideas around the concept of ‘class discipline’. It argues that under financialisation, the need for states to implement policies that discipline the working class is intensified, even if these policies do little to enable (and may even counteract) future stability. Wage restraint and punitive active labour market policies are two examples of such measures. Moreover, this disciplinary impetus has subverted and marginalised regulatory labour market institutions, rather than being embedded within them

Welfare Reform, Precarity and the Re-Commodification of Labour

While welfare reform matters for workers and workplaces, it is peripheral in English-language sociology of work and industrial relations research. This article’s core proposition is that active labour market policies (ALMPs) are altering the institutional constitution of the labour market by intensifying market discipline within the workforce. This re-commodification effect is specified drawing on Marxism, comparative institutionalism, German-language sociology, and English-language social policy analysis. Because of administrative failures and employer discrimination, however, ALMPs may worsen precarity without achieving the stated goal of increasing labour-market participation

Living on the edge: precariousness and why it matters for health

The post-war period in Europe, between the late 1940s and the 1970s, was characterised by an expansion of the role of by the state, protecting its citizens from risks of unemployment, poverty, homelessness, and food insecurity. This security began to erode in the 1980s as a result of privatisation and deregulation. The withdrawal of the state further accelerated after the 2008 financial crisis, as countries began pursuing deep austerity. The result has been a rise in what has been termed ‘precariousness’. Here we review the development of the concept of precariousness and related phenomena of vulnerability and resilience, before reviewing evidence of growing precariousness in European countries. It describes a series of studies of the impact on precariousness on health in domains of employment, housing, and food, as well as natural experiments of policies that either alleviate or worsen these impacts. It concludes with a warning, drawn from the history of the 1930s, of the political consequences of increasing precariousness in Europe and North America

Fixing it for PFA Scotland: building union influence out of a transnational project to tackle match-fixing in football

This article deploys frameworks from the fields of trade union theory and professional football governance theory to gain an understanding of the tactics deployed by the Professional Footballers’ Association, Scotland (PFAS) for collectively representing the interests of its members. The article explores how the union used the advantages gained through participation in a counter match-fixing project managed by FIFPro to establish itself as a member of an array of committees, task groups and panels so that it might become the collective ‘voice’ of players at the institutional level in football. The article commences with a review of the industrial relations landscape of professional football and the ‘peculiarities’ of the labour market that have produced equally unique trade union strategies that seek to individualise rather than collectivise wage bargaining. The implications of such a strategy are felt in the lack of appropriate contemporary theories of trade union power that might act as explanatory frameworks to aid an understanding of the tactics deployed by PFAS. The article proposes a return to a political institutional model of trade union power popularised by Sidney and Beatrice Webb in the late nineteenth-century. An analysis of interview data collected from a small cohort of expert informants shows that PFAS has taken advantage of a new body in Scottish professional football, the integrity forum, to establish itself as a credible and trustworthy voice of players within broader governing structures, while acknowledging that its sphere of influence remains constrained within a system dominated by more established institutions