314,495 research outputs found
The politics of IMFâEU cooperation : institutional change from the Maastricht Treaty to the launch of the Euro
How do regional changes affect the process of global governance? This article addresses this question by examining how the International Monetary Fund (IMF) responded to the challenges presented by Economic and Monetary Union (EMU) between the signing of the Maastricht Treaty in 1992 and the launch of the euro in 1999. Based on primary research from the IMF archives, the article illustrates how the IMF's efforts to reconfigure its relationship with European institutions evolved gradually through a logic of incremental change, despite initial opposition from member states. The article concludes that bureaucratic actors within international organizations will take advantage of informal avenues for promoting a new agenda when this fits with shared conceptions of an organization's mandate. The exercise of informal influence by advocates for change within an international organization can limit the options available to states in formal decision-making processes, even when these options cut across state preferences
Probing the Concept of Statistical Independence of Intermediate-Mass Fragment Production in Heavy-Ion Collisions
It is found that the total IMF-transverse-energy (E_t) spectra in multi-IMF
events are well represented by synthetic spectra obtained by folding of the
single-IMF spectrum. Using the experimental IMF multiplicity distribution, the
observed trends in the IMF multiplicity distribution for fixed values of E_t
are reproduced. The synthetic distributions show binomial reducibility and
Arrhenius-like scaling, similar to that reported in the literature. Similar
results are obtained when the above folding-type synthesis is replaced with one
based on mixing events with different IMF multiplicities. For statistically
independent IMF emission, the observed binomial reducibility and Arrhenius-type
scaling are merely reflections of the shape of the single-IMF transverse-energy
spectrum. Hence, a valid interpretation of IMF distributions in terms of a
particular production scenario has to explain independently the observed shape
of the single-IMF E_t spectrum.Comment: 13 pages with 8 figur
Evidence for a Turnover in the IMF of Low Mass Stars and Sub-stellar Objects: Analysis from an Ensemble of Young Clusters
We present a combined analysis of the low-mass Initial Mass Function (IMF)
for seven star forming regions. We first demonstrate that the ratios of stars
to brown dwarfs are consistent with a single underlying IMF. Assuming the
underlying IMF is the same for all seven clusters and by combining the ratio of
stars to brown dwarfs from each cluster we constrain the shape of the brown
dwarf IMF and find it to be consistent with a log--normal IMF. This provides
the strongest constraint yet that the sub-stellar IMF turns over (dN/dM
M^(-alpha), alpha < 0).Comment: 12 pages, 2 figures. Accepted in ApJ Letters Revised version have
Column 7 modified from previous versions and gramatical errors have been
correcte
The observable prestellar phase of the IMF
The observed similarities between the mass function of prestellar cores (CMF)
and the stellar initial mass function (IMF) have led to the suggestion that the
IMF is already largely determined in the gas phase. However, theoretical
arguments show that the CMF may differ significantly from the IMF. In this
Letter, we study the relation between the CMF and the IMF, as predicted by the
IMF model of Padoan and Nordlund. We show that 1) the observed mass of
prestellar cores is on average a few times smaller than that of the stellar
systems they generate; 2) the CMF rises monotonically with decreasing mass,
with a noticeable change in slope at approximately 3-5 solar masses, depending
on mean density; 3) the selection of cores with masses larger than half their
Bonnor-Ebert mass yields a CMF approximately consistent with the system IMF,
rescaled in mass by the same factor as our model IMF, and therefore suitable to
estimate the local efficiency of star formation, and to study the dependence of
the IMF peak on cloud properties; 4) only one in five pre-brown-dwarf core
candidates is a true progenitor to a brown dwarf.Comment: ApJ Letters, accepte
- âŠ