21,062 research outputs found
A Non-Reductionist Solution to the Problem of Social Causation
The thesis of the causal closure of the physical world renders mental and social causation philosophically problematic. In The Construction of Social Reality, John Searle offers a partial solution to the problem of the causal efficacy of social and institutional facts by an appeal to the notion of the Background, or, as I will argue, by an appeal to its physical components. Since Searle's solution refers to physical facts in order to explain social causation, it does not seem to differ from the solution offered by reductive physicalists to the problem of mental causation. In this paper, I will discuss both responses to these two problems of higher-order causation. As a result of this investigation, the paper offers an account of how and to what extent does Searle's solution solve the problem of the causal efficacy of social facts, without implying their reducibility to physical facts
Lorentz-violating Yang-Mills theory: discussing the Chern-Simons-like term generation
We analyze the Chern-Simons-like term generation in the CPT-odd
Lorentz-violating Yang-Mills theory interacting with fermions. Moreover, we
study the anomalies of this model as well as its quantum stability. The whole
analysis is performed within the algebraic renormalization theory, which is
independent of the renormalization scheme. In addition, all results are valid
to all orders in perturbation theory. We find that the Chern-Simons-like term
is not generated by radiative corrections, just like its Abelian version.
Additionally, the model is also free of gauge anomalies and quantum stable.Comment: 16 pages. No figures. Final version to appear in the Eur.Phys.J.
A Spitzer Study of Interacting Luminous and Ultra-Luminous Infrared Galaxies
We conducted a Spitzer Space Telescope survey of 28 Luminous (11 <
log(LIR/L_odot) < 12, LIRGs) and Ultra-Luminous Infrared Galaxies
(log(LIR/L_odot) > 12, ULIRGs). Many of these galaxies are found in pairs or
associations and are powered by either nuclear activity or starformation
(Sanders & Mirabel 1996). Our main goal is to understand the relative
importance of starbursts and AGNs in interacting systems. Is the frequency of
AGN and starbursts in these interacting galaxies related to their luminosities?
What is the importance of the merger stage and the frequency of AGNs? We
present our conclusions and diagnostic diagrams based in the observed near
infrared lines and compare to studies based solely in optical data.Comment: 3 pages, 2 figures, to appear in the Spectral Energy Distribution of
Galaxies (SED2011) conference proceedings, Preston, UK, 201
Superconducting nanobridges under magnetic fields
We report on the study of superconducting nanotips and nanobridges of lead
with a Scanning Tunnelling Microscope in tunnel and point contact regimes. We
deal with three different structures. A nanotip that remains superconducting
under a field of 2 T. For this case we present model calculations of the order
parameter, which are in good agreement with the experiments. An asymmetric
nanobridge of lead showing a two steps loss of the Andreev excess current due
to different heating and dissipation phenomena in each side of the structure. A
study of the effect of the thermal fluctuations on the Josephson coupling
between the two sides of a superconducting nanobridge submitted to magnetic
fields. The different experiments were made under magnetic fields up to twenty
five times the volume critical field of lead, and in a temperature range
between 0.6 K and 7.2 K.Comment: 17 pages, 7 figure
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