Differential Geometry of Hydrodynamic Vlasov Equations

We consider hydrodynamic chains in $(1+1)$ dimensions which are Hamiltonian with respect to the Kupershmidt-Manin Poisson bracket. These systems can be derived from single $(2+1)$ equations, here called hydrodynamic Vlasov equations, under the map $A^n =\int_{-\infty}^\infty p^n f dp.$ For these equations an analogue of the Dubrovin-Novikov Hamiltonian structure is constructed. The Vlasov formalism allows us to describe objects like the Haantjes tensor for such a chain in a much more compact and computable way. We prove that the necessary conditions found by Ferapontov and Marshall in (arXiv:nlin.SI/0505013) for the integrability of these hydrodynamic chains are also sufficient.Comment: 24 page

Editorial : from margins to centres...

Journal editorial

Segregation in search of ideology? Hegemony and contestation in the spatial and racial configuration of Los Angeles

Segregation is a constant in all US cities yet is peripheral to key work on spatial political economy, such as David Harvey (2007) and Neil Smith (1982, 1996). This thesis builds on their theorisations of the circuits of capital in relation to rent and uneven development by drawing on theorisations of white privilege (primarily Pulido, 2000) and the critical race theory of Stuart Hall (1980). Hall’s work on hegemony and articulation enables a better understanding of how the dialectics of land’s use value and rent connect to ideologies of race and neoliberalism, to city politics, and to the shifting geography of Los Angeles. The ongoing and primarily African-American struggle to occupy residential space reveals the ways in which racism and contestation have been central to the formation of Los Angeles, to the increasing privatisation of space, and to the changing flows of capital through its built environment. These issues are explored through the principal three chapters, each dedicated to an historical moment when a civil rights victory succeeded in achieving concrete shifts in the politics of race and space: the long term campaign that overturned racially restrictive covenants in 1948; the mass civil rights struggle to integrate the city’s suburbs in 1963-64; and the preservation of thousands of private residential hotel units in a gentrifying downtown in 2006. Despite their success in forcing new articulations of rationalising ideologies, politics, and capitalism’s search for a ‘spatial fix’, these struggles demonstrate that the unchanging elements in the emerging hegemony have been the prominence of force over the manufacture of consent, and the maintenance of a privileged white spatiality. I argue that a large part of neoliberalism’s power ultimately lies in its ability to rationalise and legitimate this spatiality with a colourblind discourse, masking racial inequalities and the continuing racism at the heart of US society

Interrogating the prevention approach of the Housing (Wales) Act 2014 for people with mental health needs who are homeless

Rates of homelessness and poor mental health present significant challenges across the globe. In this article, we explore how these intersecting issues have been addressed in Wales through Part 2 of the Housing (Wales) Act 2014 through a paradigm shift towards a prevention model. This article reports findings from a study (conducted between 2016 and 2018) which evaluated the processes and impacts of the Act against the backdrop of welfare reform and systemic changes taking place in Wales and the UK. Using new evidence, we offer a critical examination of how homelessness prevention policy operates in practice and how social values and power affect policy implementation. We offer new evidence of the translation of policy into practice through the experiences of two stakeholder groups: people with mental health needs and service providers. In doing so, we offer a critique of how policy and practice could be modified to improve outcomes for homeless people with implications for prevention policy in Wales and in other contexts and different welfare regimes

Urban poverty and the role of UK food aid organisations in enabling segregating and transitioning spaces of food access

This research examines the role of food aid providers, including their spatial engagement, in seeking to alleviate urban food poverty. Current levels of urban poverty across the UK have resulted in an unprecedented demand for food aid. Yet, urban poverty responsibility increasingly shifts away from policymakers to the third sector. Building on Castilhos and Dolbec’s (2018) notion of segregating space and original qualitative research with food aid organisations, we show how social supermarkets emerge as offering a type of transitional space between the segregating spaces of foodbanks and the market spaces of mainstream food retailers. This research contributes to existing literature by establishing the concept of transitional space, an additional type of space that facilitates movement between types of spaces and particularly transitions from the segregating spaces of emergency food aid to more secure spaces of food access. In so doing, this research extends Castilhos and Dolbec’s (2018) typology of spaces, enabling a more nuanced depiction of the spatiality of urban food poverty

Understanding Lived Experiences of Food Insecurity through a Paraliminality Lens

Moraes, C., McEachern, M. G., Gibbons, A. and Scullion, L. (2021). Understanding lived experiences of food poverty through a paraliminality lens. Sociology, 55(6), 1169-1190. https://doi.org/10.1177/00380385211003450. Copyright © [2021] (Copyright Holder). Reprinted by permission of SAGE Publications.This article examines lived experiences of food insecurity in the United Kingdom as a liminal phenomenon. Our research is set within the context of austerity measures, welfare reform and the precarity experienced by increasing numbers of individuals. Drawing on original qualitative data, we highlight diverse food insecurity experiences as transitional, oscillating between phases of everyday food access to requiring supplementary food, which are both empowering and reinforcing of food insecurity. We make three original contributions to existing research on food insecurity. First, we expand the scope of empirical research by conceptualising food insecurity as liminal. Second, we illuminate shared social processes and practices that intersect individual agency and structure, co-constructing people’s experiences of food insecurity. Third, we extend liminality theory by conceptualising paraliminality, a hybrid of liminal and liminoid phenomena that co-generates a persistent liminal state. Finally, we highlight policy implications that go beyond short-term emergency food access measures