3,521 research outputs found
How Participation Creates Citizens: Participatory Governance as Performative Practice
Participation is a prominent feature of many decision-making and planning processes. Among its proclaimed benefits is its potential to strengthen public support and involvement. However, participation is also known for having unintended consequences which lead to failures in meeting its objectives. This article takes a critical perspective on participation by discussing how participation may influence the ways in which citizens can become involved. Participation unavoidably involves (1) restrictions about who should be involved and about the space for negotiation, (2) assumptions about what the issue at stake is, and (3) expectations about what the outcome of participation should be and how the participants are expected to behave. This is illustrated by a case study about the Dutch nature area, the Drentsche Aa. The case study demonstrates how the participatory process that took place and the restrictions, assumptions, and expectations that were involved resulted in six forms of citizen involvement, both intended and unintended, which ranged between creativity, passivity, and entrenchment. Based on these findings, the article argues that participation does not merely serve as a neutral place in which citizens are represented, but instead creates different categories of citizens. Recognizing this means reconceiving participation as performative practice. Such a perspective goes beyond overly optimistic views of participation as a technique whose application can be perfected, as well as pessimistic views of participation as repression or domination. Instead, it appreciates both intended and unintended forms of citizen involvement as meaningful and legitimate, and recognizes citizenship as being constituted in interaction in the context of participatio
Ward identity and electrical conductivity in hot QED
We study the Ward identity for the effective photon-electron vertex summing
the ladder diagrams contributing to the electrical conductivity in hot QED at
leading logarithmic order. It is shown that the Ward identity requires the
inclusion of a new diagram in the integral equation for the vertex that has not
been considered before. The real part of this diagram is subleading and
therefore the final expressions for the electrical conductivity at leading
logarithmic order are not affected.Comment: 25 pages with 5 eps figures, discussion in section 3 improved; to
appear in JHE
Melting Spectral Functions of the Scalar and Vector Mesons in a Holographic QCD Model
We investigate the finite-temperature spectral functions of heavy quarkonia
by using the soft-wall AdS/QCD model. We discuss the scalar, the pseudo-scalar,
the vector, and the axial-vector mesons and compare their qualitative features
of the melting temperature and growing width. We find that the axial-vector
meson melts earlier than the vector meson, while there appears only a slight
difference between the scalar and pseudo-scalar mesons which also melt earlier
than the vector meson.Comment: 27 pages, 10 figure
Nonequilibrium time evolution of the spectral function in quantum field theory
Transport or kinetic equations are often derived assuming a quasi-particle
(on-shell) representation of the spectral function. We investigate this
assumption using a three-loop approximation of the 2PI effective action in real
time, without a gradient expansion or on-shell approximation. For a scalar
field in 1+1 dimensions the nonlinear evolution, including the integration over
memory kernels, can be solved numerically. We find that a spectral function
approximately described by a nonzero width emerges dynamically. During the
nonequilibrium time evolution the Wigner transformed spectral function is
slowly varying, even in presence of strong qualitative changes in the effective
particle distribution. These results may be used to make further analytical
progress towards a quantum Boltzmann equation including off-shell effects and a
nonzero width.Comment: 20 pages with 6 eps figures, explanation and references added; to
appear in Phys.Rev.
Exact and Truncated Dynamics in Nonequilibrium Field Theory
Nonperturbative dynamics of quantum fields out of equilibrium is often
described by the time evolution of a hierarchy of correlation functions, using
approximation methods such as Hartree, large N, and nPI-effective action
techniques. These truncation schemes can be implemented equally well in a
classical statistical system, where results can be tested by comparison with
the complete nonlinear evolution obtained by numerical methods. For a 1+1
dimensional scalar field we find that the early-time behaviour is reproduced
qualitatively by the Hartree dynamics. The inclusion of direct scattering
improves this to the quantitative level. We show that the emergence of
nonthermal temperature profiles at intermediate times can be understood in
terms of the fixed points of the evolution equations in the Hartree
approximation. The form of the profile depends explicitly on the initial
ensemble. While the truncated evolution equations do not seem to be able to get
away from the fixed point, the full nonlinear evolution shows thermalization
with a (surprisingly) slow relaxation.Comment: 30 pages with 12 eps figures, minor changes; to appear in Phys.Rev.
The equilibrium intrinsic crystal-liquid interface of colloids
We use confocal microscopy to study an equilibrated crystal-liquid interface
in a colloidal suspension. Capillary waves roughen the surface, but locally the
intrinsic interface is sharply defined. We use local measurements of the
structure and dynamics to characterize the intrinsic interface, and different
measurements find slightly different widths of this interface. In terms of the
particle diameter , this width is either (based on structural
information) or (based on dynamics), both not much larger than the
particle size. This work is the first direct experimental visualization of an
equilibrated crystal-liquid interface.Comment: 6 pages; revised version, submitted to PNA
Issues, Discontent, and Third-Party Voting: The Case of the Netherlands
Scholarly accounts of the dramatic breakthrough of the List Pim Fortuyn (LPF) in the 2002
Dutch parliamentary election have mostly emphasized two factors behind the success of
that party. It has first been argued that the LPF brought a distinct issue profile to the
electoral arena, which made it attractive for voters holding similar policy views. The
second hypothesis, that feelings of political discontent also fuelled support for the LPF,
remains highly contested because of the possible endogeneity bias of cynicism attitudes.
We re-examine this question using survey data from the 1998-2002 panel of the Dutch
National Election Study. Our approach’s novelty is to estimate 2002’s vote choice using
indicators of individuals’ issue priorities and cynical attitudes as measured in the 1998
wave of the panel. The findings suggest that policy preferences and attitudes of discontent
both contributed to the LPF vote, thus providing support for both interpretations of the rise
of this party. These results are consistent with most existing work on “third” or minor party
voting showing that lack of confidence toward government and politics is fertile ground for
these party movements.Session 2: Political representation and legitimac
Thermal effects on slow-roll dynamics
A description of the transition from the inflationary epoch to radiation
domination requires the understanding of quantum fields out of thermal
equilibrium, particle creation and thermalisation. This can be studied from
first principles by solving a set of truncated real-time Schwinger-Dyson
equations, written in terms of the mean field (inflaton) and the field
propagators, derived from the two-particle irreducible effective action. We
investigate some aspects of this problem by considering the dynamics of a
slow-rolling mean field coupled to a second quantum field, using a \phi^2\chi^2
interaction. We focus on thermal effects. It is found that interactions lead to
an earlier end of slow-roll and that the evolution afterwards depends on
details of the heatbath.Comment: 25 pages, 11 eps figures. v2: paper reorganized, title changed,
conclusions unchanged, to appear in PR
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