722 research outputs found
I love the smell of napalm in the morning: aesthetics against society
The relationship of aesthetics to ethics is explored through a discussion of late nineteenth- and early twentieth-century Japanese military woodblock prints and recent Daesh (ISIL) media productions. Ruth Benedict’s The Chrysanthemum and the Sword is praised for its anthropological ‘nearness’ to a ‘dangerous’ local aesthetics and ethics, a ‘proximity’ that philosophers of aesthetics seem reluctant to entertain. Thierry de Duve’s engagement with Kant’s sensus communis (which creates the ‘oughtness’ of art) is invoked to help explain why politics is always inextricably aestheticized and aesthetics always intrinsically political
Prophetic Pictures Or: What Time is the visual?
This chapter attempts to anchor the dialectic between the representation of antecedent signifiers and futurity in the specific context of a corpus of illustrated nineteenth-century astrological almanacs before then striking out to attempt to explore the unlikely prophetic echoes apparent in photography. The Pythoness of the East, and Raphael’s nominalist appropriation of a Jewish identity, points to the Prophetic Messenger’s role as an agent of cultural critique. In fact, Raphael’s usage owed more to the Renaissance fantasy of picture-writing descended from Francesco Colonna’s Hypnerotomachia Poliphili first published by Aldus Manutius in 1499 in Venice. Raphael’s almanacs were striking for the prominence given to a ‘prophetic hieroglyphic’ published as a frontispiece to each annual issue. This nineteenth-century usage echoes Walter Benjamin’s sense of a ‘picture-writing’ descended from the great Renaissance text Hypnerotomachia Poliphili. For Benjamin, as for Pierre Bourdieu, photographs are allegories, but they are portents of a future for which there might be a key
Strong geometric frustration in model glassformers
We consider three popular model glassformers, the Kob-Andersen and
Wahnstr\"om binary Lennard-Jones models and weakly polydisperse hard spheres.
Although these systems exhibit a range of fragilities, all feature a rather
similar behaviour in their local structure approaching dynamic arrest. In
particular we use the dynamic topological cluster classification to extract a
locally favoured structure which is particular to each system. These structures
form percolating networks, however in all cases there is a strong decoupling
between structural and dynamic lengthscales. We suggest that the lack of growth
of the structural lengthscale may be related to strong geometric frustration.Comment: 14 pages, Accepted by J. Non-Crystalline Solids, 7th International
Discussion Meeting on Relaxation in Complex Systems Proceeding
Yielding of a Model Glassformer: an Interpretation with an Effective System of Icosahedra
We consider the yielding under simple shear of a binary Lennard-Jones
glassformer whose super-Arrhenius dynamics are correlated with the formation of
icosahedral structures. We recast this glassformer as an effective system of
icosahedra [Pinney et al. J. Chem. Phys. 143 244507 (2015)]. Looking at the
small-strain region of sheared simulations, we observe that shear rates affect
the shear localisation behavior particularly at temperatures below the glass
transition as defined with a fit to the Vogel-Fulcher-Tamman equation. At
higher temperature, shear localisation starts immediately upon shearing for all
shear rates. At lower temperatures, faster shear rates can result in a delayed
start in shear localisation; which begins close to the yield stress. Building
from a previous work which considered steady-state shear [Pinney et al. J.
Chem. Phys. 143 244507 (2016)], we interpret the response to shear and the
shear localisation in terms of a \emph{local} effective temperature with our
system of icosahedra. We find that the effective temperatures of the regions
undergoing shear localisation increase significantly with increasing strain
(before reaching a steady state plateau).Comment: 13 pages, accepted in Phys. Rev.
Structure in sheared supercooled liquids:Dynamical rearrangements of an effective system of icosahedra
We consider a binary Lennard-Jones glassformer whose super-Arrhenius dynamics
are correlated with the formation of particles organized into icosahedra under
simple steady state shear. We recast this glassformer as an effective system of
icosahedra [Pinney et al. J. Chem. Phys. 143 244507 (2015)]. From the observed
population of icosahedra in each steady state, we obtain an effective
temperature which is linearly dependent on the shear rate in the range
considered. Upon shear banding, the system separates into a region of high
shear rate and a region of low shear rate. The effective temperatures obtained
in each case show that the low shear regions correspond to a significantly
lower temperature than the high shear regions. Taking a weighted average of the
effective temperature of these regions (weight determined by region size)
yields an estimate of the effective temperature which compares well with an
effective temperature based on the global mesocluster population of the whole
system.Comment: accepted by J. Chehm. Phy
Recasting a model atomistic glassformer as a system of icosahedra
We consider a binary Lennard-Jones glassformer whose super-Arrhenius dynamics
are correlated with the formation of icosahedral structures. Upon cooling these
icosahedra organize into mesoclusters. We recast this glassformer as an
effective system of icosahedra which we describe with a population dynamics
model. This model we parameterize with data from the temperature regime
accessible to molecular dynamics simulations. We then use the model to
determine the population of icosahedra in mesoclusters at arbitrary
temperature. Using simulation data to incorporate dynamics into the model we
predict relaxation behavior at temperatures inaccessible to conventional
approaches. Our model predicts super-Arrhenius dynamics whose relaxation time
remains finite for non-zero temperature.Comment: 10 pages, 9 figure
Nonlinearity Management in Higher Dimensions
In the present short communication, we revisit nonlinearity management of the
time-periodic nonlinear Schrodinger equation and the related averaging
procedure. We prove that the averaged nonlinear Schrodinger equation does not
support the blow-up of solutions in higher dimensions, independently of the
strength in the nonlinearity coefficient variance. This conclusion agrees with
earlier works in the case of strong nonlinearity management but contradicts
those in the case of weak nonlinearity management. The apparent discrepancy is
explained by the divergence of the averaging procedure in the limit of weak
nonlinearity management.Comment: 9 pages, 1 figure
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