9,446 research outputs found
Conceptualizing cultures of violence and cultural change
The historiography of violence has undergone a distinct cultural turn as attention has shifted from examining violence as a clearly defined (and countable) social problem to analysing its historically defined 'social meaning'. Nevertheless, the precise nature of the relationship between 'violence' and 'culture' is still being established. How are 'cultures of violence' formed? What impact do they have on violent behaviour? How do they change? This essay examines some of the conceptual aspects of the relationship between culture and violence. It brings together empirical research into nineteenth-century England with recent research results from other European contexts to examine three aspects of the relationship between culture and violence. These are organised under the labels 'seeing violence', 'identifying the violent' and 'changing violence'. Within a particular society, narratives regarding particular kinds of behaviour shape cultural attitudes. The notion 'violence' is thus defined in relation to physically aggressive acts as well as by being connected to other kinds of attitudes and contexts. As a result, the boundaries between physical aggression which is legitimate and that which is illegitimate (and thus 'violence') are set. Once 'violence' is defined, particular cultures form ideas about who is responsible for it: reactions to violence become associated with social arrangements such as class and gender as well as to attitudes toward the self. Finally, cultures of violence make efforts to tame or eradicate illegitimate forms of physical aggression. This process is not only connected to the development of new forms of power (e.g., new policing or punishment strategies) but also to less tangible cultural influences which aim at changing the behaviour defined as violence (in particular among the social groups identified as violent). Even if successful, this three-tiered process of seeing violence, identifying the violent and changing violence continues anew, emphasising the ways that cultures of violence develop through a continuous process of reevaluation and reinvention
The supernova impostor PSN J09132750+7627410 and its progenitor
We report the results of our follow-up campaign of the supernova impostor PSN
J09132750+7627410, based on optical data covering . From the
beginning, the transient shows prominent narrow Balmer lines with P-Cygni
profiles, with a blue-shifted absorption component becoming more prominent with
time. Along the of the spectroscopic monitoring, broad
components are never detected in the hydrogen lines, suggesting that these
features are produced in slowly expanding material. The transient reaches an
absolute magnitude at maximum, a typical
luminosity for supernova impostors. Amateur astronomers provided
of archival observations of the host galaxy, NGC 2748. The
detection of the quiescent progenitor star in archival images obtained with the
Hubble Space Telescope suggests it to be an \msun white-yellow
supergiant.Comment: 7 pages, 4 figures, supplemental material available in the source
file. Accepted for publication on Astrophysical Journal Letter
Comparing and characterizing some constructions of canonical bases from Coxeter systems
The Iwahori-Hecke algebra of a Coxeter system has a
"standard basis" indexed by the elements of and a "bar involution" given by
a certain antilinear map. Together, these form an example of what Webster calls
a pre-canonical structure, relative to which the well-known Kazhdan-Lusztig
basis of is a canonical basis. Lusztig and Vogan have defined a
representation of a modified Iwahori-Hecke algebra on the free
-module generated by the set of twisted involutions in
, and shown that this module has a unique pre-canonical structure satisfying
a certain compatibility condition, which admits its own canonical basis which
can be viewed as a generalization of the Kazhdan-Lusztig basis. One can modify
the parameters defining Lusztig and Vogan's module to obtain other
pre-canonical structures, each of which admits a unique canonical basis indexed
by twisted involutions. We classify all of the pre-canonical structures which
arise in this fashion, and explain the relationships between their resulting
canonical bases. While some of these canonical bases are related in a trivial
fashion to Lusztig and Vogan's construction, others appear to have no simple
relation to what has been previously studied. Along the way, we also clarify
the differences between Webster's notion of a canonical basis and the related
concepts of an IC basis and a -kernel.Comment: 32 pages; v2: additional discussion of relationship between canonical
bases, IC bases, and P-kernels; v3: minor revisions; v4: a few corrections
and updated references, final versio
Renormalization-Scale Invariance, Minimal Sensitivity, and the Inclusive Hadronic Decays of a 115 GeV Higgs Particle
Known perturbative expressions for the decay rates of 115 GeV Higgs particle
into either two gluons or a pair are shown to exhibit
renormalization-scale-()-dependence that is largely removed via
renormalization-group/Pade-approximant estimates of these rates' next order
contributions. The extrema in characterizing both rates, as determined
from fully-known orders of perturbation theory, are very nearly equal to
corresponding -insensitive rates obtained via estimation of their next
order contributions, consistent with "minimal-sensitivity" expectations.Comment: 12 pages, 3 figures, LaTe
The absolute infrared magnitudes of type Ia supernovae
The absolute luminosities and homogeneity of early-time infrared (IR) light
curves of type Ia supernovae are examined. Eight supernovae are considered.
These are selected to have accurately known epochs of maximum blue light as
well as having reliable distance estimates and/or good light curve coverage.
Two approaches to extinction correction are considered. Owing to the low
extinction in the IR, the differences in the corrections via the two methods
are small. Absolute magnitude light curves in the J, H and K-bands are derived.
Six of the events, including five established ``Branch-normal'' supernovae show
similar coeval magnitudes. Two of these, SNe 1989B and 1998bu, were observed
near maximum infrared light. This occurs about 5 days {\it before} maximum blue
light. Absolute peak magnitudes of about -19.0, -18.7 and -18.8 in J, H & K
respectively were obtained. The two spectroscopically peculiar supernovae in
the sample, SNe 1986G and 1991T, also show atypical IR behaviour. The light
curves of the six similar supernovae can be represented fairly consistently
with a single light curve in each of the three bands. In all three IR bands the
dispersion in absolute magnitude is about 0.15 mag, and this can be accounted
for within the uncertainties of the individual light curves. No significant
variation of absolute IR magnitude with B-band light curve decline rate, Delta
m_{15}(B), is seen over the range 0.87<Delta m_{15}(B)<1.31. However, the data
are insufficient to allow us to decide whether or not the decline rate relation
is weaker in the IR than in the optical region. IR light curves of type Ia
supernovae should eventually provide cosmological distance estimates which are
of equal or even superior quality to those obtained in optical studies.Comment: 19 pages, 9 figures, MNRAS in press (includes Referee's changes
Massive stars exploding in a He-rich circumstellar medium - VIII. PSN J07285387+3349106, a highly reddened supernova Ibn
We present spectroscopic and photometric observations for the Type Ibn
supernova (SN) dubbed PSN J07285387+3349106. Using data provided by amateur
astronomers, we monitored the photometric rise of the SN to maximum light,
occurred on 2015 February 18.8 UT (JD(max,V) = 2457072.0 +- 0.8). PSN
J07285387+3349106 exploded in the inner region of an infrared luminous galaxy,
and is the most reddened SN Ibn discovered so far. We apply multiple methods to
derive the total reddening to the SN, and determine a total colour excess
E(B-V)(tot) = 0.99 +- 0.48 mag. Accounting for the reddening correction, which
is affected by a large uncertainty, we estimate a peak absolute magnitude of
M(V) = -20.30 +- 1.50. The spectra are dominated by continuum emission at early
phases, and He I lines with narrow P-Cygni profiles are detected. We also
identify weak Fe III and N II features. All these lines show an absorption
component which is blue-shifted by about 900-1000 km/s. The spectra also show
relatively broad He I line wings with low contrast, which extend to above 3000
km/s. From about 2 weeks past maximum, broad lines of O I, Mg II and the Ca II
near-infrared triplet are identified. The composition and the expansion
velocity of the circumstellar material, and the presence of He I and
alpha-elements in the SN ejecta indicate that PSN J07285387+3349106 was
produced by the core-collapse of a stripped-envelope star. We suggest that the
precursor was WNE-type Wolf-Rayet star in its dense, He-rich circumstellar
cocoon.Comment: 12 pages, 7 figures, 2 tables. Accepted for publication in MNRA
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