1,038 research outputs found
Causation, Measurement Relevance and No-conspiracy in EPR
In this paper I assess the adequacy of no-conspiracy conditions employed in
the usual derivations of the Bell inequality in the context of EPR
correlations. First, I look at the EPR correlations from a purely
phenomenological point of view and claim that common cause explanations of
these cannot be ruled out. I argue that an appropriate common cause explanation
requires that no-conspiracy conditions are re-interpreted as mere common
cause-measurement independence conditions. In the right circumstances then,
violations of measurement independence need not entail any kind of conspiracy
(nor backwards in time causation). To the contrary, if measurement operations
in the EPR context are taken to be causally relevant in a specific way to the
experiment outcomes, their explicit causal role provides the grounds for a
common cause explanation of the corresponding correlations.Comment: 20 pages, 1 figur
Nebuliser therapy in the intensive care unit
The relationship between identity, lived experience, sexual practices and the language through which these are conveyed has been widely debated in sexuality literature. For example, ‘coming out’ has famously been conceptualised as a ‘speech act’ (Sedgwick 1990) and as a collective narrative (Plummer 1995), while a growing concern for individuals’ diverse identifications in relations to their sexual and gender practices has produced interesting research focusing on linguistic practices among LGBT-identified individuals (Leap 1995; Kulick 2000; Cameron and Kulick 2006; Farqhar 2000). While an explicit focus on language remains marginal to literature on sexualities (Kulick 2000), issue of language use and translation are seldom explicitly addressed in the growing literature on intersectionality. Yet intersectional perspectives ‘reject the separability of analytical and identity categories’ (McCall 2005:1771), and therefore have an implicit stake in the ‘vernacular’ language of the researched, in the ‘scientific’ language of the researcher and in the relationship of continuity between the two. Drawing on literature within gay and lesbian/queer studies and cross-cultural studies, this chapter revisits debates on sexuality, language and intersectionality. I argue for the importance of giving careful consideration to the language we choose to use as researchers to collectively define the people whose experiences we try to capture. I also propose that language itself can be investigated as a productive way to foreground how individual and collective identifications are discursively constructed, and to unpack the diversity of lived experience. I address intersectional complexity as a methodological issue, where methodology is understood not only as the methods and practicalities of doing research, but more broadly as ‘a coherent set of ideas about the philosophy, methods and data that underlie the research process and the production of knowledge’ (McCall 2005:1774). My points are illustrated with examples drawn from my ethnographic study on ‘lesbian’ identity in urban Russia, interspersed with insights from existing literature. In particular, I aim to show that an explicit focus on language can be a productive way to explore the intersections between the global, the national and the local in cross-cultural research on sexuality, while also addressing issues of positionality and accountability to the communities researched
Renormalization Group Analysis of a Noisy Kuramoto-Sivashinsky Equation
We have analyzed the Kuramoto-Sivashinsky equation with a stochastic noise
term through a dynamic renormalization group calculation. For a system in which
the lattice spacing is smaller than the typical wavelength of the linear
instability occurring in the system, the large-distance and long-time behavior
of this equation is the same as for the Kardar-Parisi-Zhang equation in one and
two spatial dimensions. For the case the agreement is only qualitative.
On the other hand, when coarse-graining on larger scales the asymptotic flow
depends on the initial values of the parameters.Comment: 8 pages, 5 figures, revte
Decoherence, the measurement problem, and interpretations of quantum mechanics
Environment-induced decoherence and superselection have been a subject of
intensive research over the past two decades, yet their implications for the
foundational problems of quantum mechanics, most notably the quantum
measurement problem, have remained a matter of great controversy. This paper is
intended to clarify key features of the decoherence program, including its more
recent results, and to investigate their application and consequences in the
context of the main interpretive approaches of quantum mechanics.Comment: 41 pages. Final published versio
The radio/gamma-ray connection in Active Galactic Nuclei in the era of the Fermi Large Area Telescope
We present a detailed statistical analysis of the correlation between radio
and gamma-ray emission of the Active Galactic Nuclei (AGN) detected by Fermi
during its first year of operation, with the largest datasets ever used for
this purpose. We use both archival interferometric 8.4 GHz data (from the VLA
and ATCA, for the full sample of 599 sources) and concurrent single-dish 15 GHz
measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of
199 objects). Our unprecedentedly large sample permits us to assess with high
accuracy the statistical significance of the correlation, using a
surrogate-data method designed to simultaneously account for common-distance
bias and the effect of a limited dynamical range in the observed quantities. We
find that the statistical significance of a positive correlation between the cm
radio and the broad band (E>100 MeV) gamma-ray energy flux is very high for the
whole AGN sample, with a probability <1e-7 for the correlation appearing by
chance. Using the OVRO data, we find that concurrent data improve the
significance of the correlation from 1.6e-6 to 9.0e-8. Our large sample size
allows us to study the dependence of correlation strength and significance on
specific source types and gamma-ray energy band. We find that the correlation
is very significant (chance probability <1e-7) for both FSRQs and BL Lacs
separately; a dependence of the correlation strength on the considered
gamma-ray energy band is also present, but additional data will be necessary to
constrain its significance.Comment: Accepted for publications by ApJ. Contact authors: M. Giroletti, V.
Pavlidou, A. Reime
Assessing the impact of area-based initiatives in deprived neighborhoods: The example of S. João de Deus in Porto, Portugal
Though there have been many area-based initiatives to regenerate rundown areas in numerous cities around the world, many of them involving the demolition of stigmatized housing estates, far fewer attempts have been made to assess the effects of these initiatives upon the fortunes of displaced households and those who remain in these areas. By presenting the results of an empirical in-depth case study on the effects of an area-based initiative targeted at one of the most deprived neighborhoods in Porto, this article raises several epistemological concerns related to the goals, ideological assumptions, and social and spatial effects of these initiatives. Among other interrelated issues, the article discusses the impact of conflicting ideologies upon processes of radical strategy shift and of social and territorial marginalization and appeals to the need for more pluralistic approaches to evaluation.I gratefully acknowledge the financial support of the Portuguese Fundação para a Ciência e Tecnologia for research grant SFRH/BPD/75863/2011, POPH/FSE
The Spectral Energy Distribution of Fermi bright blazars
(Abridged) We have conducted a detailed investigation of the broad-band
spectral properties of the \gamma-ray selected blazars of the Fermi LAT Bright
AGN Sample (LBAS). By combining our accurately estimated Fermi gamma-ray
spectra with Swift, radio, infra-red, optical and other hard X-ray/gamma-ray
data, collected within three months of the LBAS data taking period, we were
able to assemble high-quality and quasi-simultaneous Spectral Energy
Distributions (SED) for 48 LBAS blazars.The SED of these gamma-ray sources is
similar to that of blazars discovered at other wavelengths, clearly showing, in
the usual Log - Log F representation, the typical broad-band
spectral signatures normally attributed to a combination of low-energy
synchrotron radiation followed by inverse Compton emission of one or more
components. We have used these SEDs to characterize the peak intensity of both
the low and the high-energy components. The results have been used to derive
empirical relationships that estimate the position of the two peaks from the
broad-band colors (i.e. the radio to optical and optical to X-ray spectral
slopes) and from the gamma-ray spectral index. Our data show that the
synchrotron peak frequency is positioned between 10 and
10 Hz in broad-lined FSRQs and between and Hz in
featureless BL Lacertae objects.We find that the gamma-ray spectral slope is
strongly correlated with the synchrotron peak energy and with the X-ray
spectral index, as expected at first order in synchrotron - inverse Compton
scenarios. However, simple homogeneous, one-zone, Synchrotron Self Compton
(SSC) models cannot explain most of our SEDs, especially in the case of FSRQs
and low energy peaked (LBL) BL Lacs. (...)Comment: 85 pages, 38 figures, submitted to Ap
A review of assessment methods for river hydromorphology
The work leading to this paper has received funding for the EU’s FP7 under Grant Agreement No. 282656 (REFORM
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