360 research outputs found
Shear Viscosities from Kubo Formalism in a large- Nambu--Jona-Lasinio Model
In this work the shear viscosity of strongly interacting matter is calculated
within a two-flavor Nambu--Jona-Lasinio model as a function of temperature and
chemical potential. The general Kubo formula is applied, incorporating the full
Dirac structure of the thermal quark spectral function and avoiding commonly
used on-shell approximations. Mesonic fluctuations contributing via Fock
diagrams provide the dominant dissipative processes. The resulting ratio
(shear viscosity over entropy density) decreases with temperature and
chemical potential. Interpolating between our NJL results at low temperatures
and hard-thermal-loop results at high temperatures a minimum slightly above the
AdS/CFT benchmark is obtained.Comment: 15 pages, 11 figures. Revision with minor corrections matches
published versio
Transnational practices governing European integration: executive autonomy and neo-corporatist concertation in the steel sector
Musealizing the European Union and Its History: Institutions, Actors and Networks
The two chapters employ the concepts of MLG and networks to capture the character of the politics and policy-making of cultural policy in the EU with a particular focus on more recent attempts at the Europeanisation of (history) museums through (inter alia) changing their content and narratives. The concepts are, however, employed as heuristic tools only in these draft chapters for a book written for a cross-disciplinary audience and a larger market including museum practitioners. The research is based on wide-ranging document analysis, visits to and the analysis of some 90 museums and temporary exhibitions across Europe and some 60 interviews with politicians and officials involved in cultural policy making in state institutions at European and national levels as as well as societal actors including NGOs, historians and museum directors and curators.
The core arguments in these two draft chapters and this part of the forthcoming book are as follows:
1. Due to the EUâs still very limited formal competences in cultural policy and the crucial importance of this policy field for national and regional polities and identities, politics and policy-making in the field of culture is very highly fragmented. As a result, the limited existing works by sociologists like Chris Shore and political scientists like Tobais Theiler and Annabelle Littoz-Monnet (for references see the bibliography at the end of the draft chapters), which focus exclusively on âBrusselsâ, fail to capture the complexity of this field.
2. My draft chapters and our book aim to overcome these limits with a two-fold strategy: first, I broaden the perspective to discuss a multitude of state actors in the specific field of musealization of the European Union and European integration to include national and especially regional actors. The research shows that regional actors in cultural fragmented and constitutionally decentralized or federal member-states buy
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into the Europeanization agenda because it strengthens regional narratives and
identities. Even in member-states like France with constitutionally comparatively
weak regions, but quite strong regional identities in some parts, some regions strongly
support the European embedding of their museal representation strategies to enhance
the legitimacy of their powers and to strengthen regional identity.
3. Secondly, I argue that it is crucially necessary to go beyond the study of state actors in
the museum field (and cultural heritage more generally). In the second chapter I
discuss the role of professional groups (esp. historians and museum practitioners) in
the Europeanization processes we observe, their partly formalized but largely informal
networking activities and the particular role of individual cultural entrepreneurs. This
broadly transnational sociological perspective demonstrates that attempts to
transnationalize and Europeanize museal narratives are to a large degree driven from
below and not entirely dependent on EU initiative or funding, although they draw
upon it wherever possible.
4. This research challenges in particular the strongly normative idea in Shore (2000) and
similar works that the EU approach to cultural policy is hierarchical and instrumental
and that this is outdated and bad. Instead, cultural politics and policy-making is best
understood as a highly disorganized and chaotic field with multiple state and non-state
actors with very different motivations and objectives. Even at EU level, the politics
and policy-making of cultural integration is less geared towards policy-making than
what might be called project-making, i.e. inserting particular agendas and ideas into
funding priorities and funding streams and obtaining such funding.
5. Moreover, the research also demonstrates that rational choice explanations are of
limited value for assessing the motivations of the multiple actors in this field, and in
the particular area of Europeanization of museums and historical narratives. It
becomes clear that many societal actors in particular are not just driven by gaining
access to funding. In fact, such funding is often insignificant, esp. in the Culture 2007-
13 programme as opposed to Interreg funding, for example, its administration is
excessively bureaucratic and its function is at best that of providing seed funding to
facilitate the establishment of more long-term cross-national forms of cooperation
among relevant actors like museums. Rather, many of the non-state actors are mainly
driven by their ideational beliefs. They include (inter alia) a strong belief that national
narratives, which have derived from nineteenth-century nationalism, are outmoded;
that museums have to transnationalize their working methods and content; that this
often means Europeanizing their content and narratives in the first instance, esp. in
member-states without a colonial tradition or non-European inward-migration; that in
representations of contemporary history this might mean strengthening references to
the EU, but less as an institutional space of politics and policy-making and more as a
economic and social space of ever closer communication and interaction; and that
such a transformation of museums and their content and narratives can also act as a
barrier against nationalist populist movements and political parties which have
recently had electoral success in member-states like Sweden, Denmark and the
Netherlands.
6. At the most general level, the draft chapters and the book as a whole argue strongly for
a perspective on culture and âEuropeâ, the EU and European integration which is
much less Brussels-centred and much less state-centric in its treatment of âBrusselsâ.
At the most general level, the chapters and the book also advocate a strongly transdisciplinary
cooperation across the social sciences and humanities which helps to
overcome the excessive focus of the limited political science research in this field on
state institutions and policy-making and of sociological research on âBrusselsâ and
EU-level elites neglecting the transnational and transnational elites
Nuclear density functional constrained by low-energy QCD
We have developed a relativistic point-coupling model of nuclear many-body
dynamics constrained by the low-energy sector of QCD. The effective Lagrangian
is characterized by density-dependent coupling strengths determined by chiral
one- and two-pion exchange (with single and double delta isobar excitations)
and by large isoscalar background fields that arise through changes of the
quark condensate and the quark density at finite baryon density. The model has
been tested in the analysis of nuclear ground-state properties along different
isotope chains of medium and heavy nuclei. The agreement with experimental data
is comparable with purely phenomenological predictions. The built-in QCD
constraints and the explicit treatment of pion exchange restrict the freedom in
adjusting parameters and functional forms of density-dependent couplings. It is
shown that chiral pionic fluctuations play an important role for nuclear
binding and saturation mechanism, whereas background fields of about equal
magnitude and opposite sign generate the effective spin-orbit potential in
nuclei.Comment: ws-procs9x6.cls, 8 pgs, Talk presented at "X Convegno su Problemi di
Fisica Nucleare Teorica", Cortona (AR), 6-9 october 200
Alpha-clustered hypernuclei and chiral SU(3) dynamics
Light hypernuclei with an cluster substructure of the core nucleus
are studied using an accurate cluster approach (the Hyper-THSR wave function)
in combination with a density-dependent hyperon-nuclear interaction
derived from chiral SU(3) effective field theory. This interaction includes
important two-pion exchange processes involving intermediate states
and associated three-body mechanisms as well as effective mass and surface
terms arising in a derivative expansion of the in-medium self-energy.
Applications and calculated results are presented and discussed for
Be and C. Furthermore, the result of the lightest
clustered hypernucleus, He using realistic
four nucleon density is shown.Comment: To be submitted in PTE
Clash of Cultures: Two Milieus in the European Union's âA New Narrative for Europeâ Project
Nuclear thermodynamics from chiral low-momentum interactions
We investigate the thermodynamic equation of state of isospin-symmetric
nuclear matter with microscopic nuclear forces derived within the framework of
chiral effective field theory. Two- and three-body nuclear interactions
constructed at low resolution scales form the basis for a perturbative
calculation of the finite-temperature equation of state. The nuclear force
models and many-body methods are benchmarked against bulk properties of
isospin-symmetric nuclear matter at zero temperature, which are found to be
well reproduced when chiral nuclear interactions constructed at the lowest
resolution scales are employed. The calculations are then extended to finite
temperatures, where we focus on the liquid-gas phase transition and the
associated critical point. The Maxwell construction is applied to construct the
physical equation of state, and the value of the critical temperature is
determined to be T_c =17.2-19.1 MeV, in good agreement with the value extracted
from multifragmentation reactions of heavy ions.Comment: 22 pages, 12 figures, 2 tables. v3 matches published versio
Transnaionalism and early European integration: the Nouvelles Equipes Internationales and the Geneva Circle 1947â1957
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