2,179 research outputs found
Education movies and the promotion of one dimensional thinking: a marcusean examination of films made between 2005 and 2017
This thesis examines how recent movies have depicted schools and teachers in the United Kingdom and the United States. Deploying methodological tools outlined by the Frankfurt School critical theorist Herbert Marcuse, it analyses the messages of twenty-first century film-making in the school genre, asking whether such films reinforce or challenge neoliberal perspectives of education.
To address this, ten films are assessed against Marcuse’s most significant and well-known philosophical concept - ‘one-dimensionality’ - modes of thinking in ‘advanced capitalist societies’ where critical spaces and alternative ways of seeing the world are closed down.
To analyse whether films contribute to a ‘one-dimensional’ perspective of education, key Marcusean constructs are utilised, concepts that Marcuse argued contributed to the death of critical thinking. The films are analysed through the main written method of the Frankfurt School – the dialectic.
Through the combined dialectical analysis of ten films, literature in the field and through exploration of critical theory and Marcuse, this thesis argues that movies play an important role in the consolidation of neoliberal perspectives of education, and that awareness and examination of the impact of popular culture should remain a significant feature of any critical society. In so doing, the thesis also aims to critically contribute towards a recent ‘renaissance’ in the consideration and application of Marcuse’s scholarly output
A homogenization theorem for Langevin systems with an application to Hamiltonian dynamics
This paper studies homogenization of stochastic differential systems. The
standard example of this phenomenon is the small mass limit of Hamiltonian
systems. We consider this case first from the heuristic point of view,
stressing the role of detailed balance and presenting the heuristics based on a
multiscale expansion. This is used to propose a physical interpretation of
recent results by the authors, as well as to motivate a new theorem proven
here. Its main content is a sufficient condition, expressed in terms of
solvability of an associated partial differential equation ("the cell
problem"), under which the homogenization limit of an SDE is calculated
explicitly. The general theorem is applied to a class of systems, satisfying a
generalized detailed balance condition with a position-dependent temperature.Comment: 32 page
Massless and massive graviton spectra in anisotropic dilatonic braneworld cosmologies
We consider a braneworld model in which an anisotropic brane is embedded in a
dilatonic background. We solve the background solutions and study the behavior
of the perturbations when the universe evolves from an inflationary Kasner
phase to a Minkowski phase. We calculate the massless mode spectrum, and find
that it does not differ from what expected in standard four-dimensional
cosmological models. We then evaluate the spectrum of both light
(ultrarelativistic) and heavy (nonrelativistic) massive modes, and find that,
at high energies, there can be a strong enhancement of the Kaluza-Klein
spectral amplitude, which can become dominant in the total spectrum. The
presence of the dilaton, on the contrary, decrease the relative importance of
the massive modes.Comment: 18 pages, 4 figures, Typos correction
Soliton Solutions to the Einstein Equations in Five Dimensions
We present a new class of solutions in odd dimensions to Einstein's equations
containing either a positive or negative cosmological constant. These solutions
resemble the even-dimensional Eguchi-Hanson--(anti)-de Sitter ((A)dS) metrics,
with the added feature of having Lorentzian signatures. They provide an
affirmative answer to the open question as to whether or not there exist
solutions with negative cosmological constant that asymptotically approach
AdS, but have less energy than AdS. We present
evidence that these solutions are the lowest-energy states within their
asymptotic class.Comment: 9 pages, Latex; Final version that appeared in Phys. Rev. Lett; title
changed by journal from original title "Eguchi-Hanson Solitons
Particle production and reheating in the inflationary universe
Thermal field theory is applied to particle production rates in inflationary
models, leading to new results for catalysed, or two-stage decay, where massive
fields act as decay channels for the production of light fields. A numerical
investigation of the Bolztmann equation in an expanding universe shows that the
particle distributions produced during small amplitude inflaton oscillations or
alongside slowly moving inflaton fields can thermalise.Comment: 16 pages, 12 figures, LaTeX, extra references in v
Population bound effects on bosonic correlations in non-inertial frames
We analyse the effect of bounding the occupation number of bosonic field
modes on the correlations among all the different spatial-temporal regions in a
setting in which we have a space-time with a horizon along with an inertial
observer. We show that the entanglement between A (inertial observer) and R
(uniformly accelerated observer) depends on the bound N, contrary to the
fermionic case. Whether or not decoherence increases with N depends on the
value of the acceleration a. Concerning the bipartition A-antiR (Alice with an
observer in Rindler's region IV), we show that no entanglement is created
whatever the value of N and a. Furthermore, AR entanglement is very quickly
lost for finite N and for infinite N. We will study in detail the mutual
information conservation law found for bosons and fermions. By means of the
boundary effects associated to N finiteness, we will show that for bosons this
law stems from classical correlations while for fermions it has a quantum
origin. Finally, we will present the strong N dependence of the entanglement in
R-antiR bipartition and compare the fermionic cases with their finite N bosonic
analogs. We will also show the anti-intuitive dependence of this entanglement
on statistics since more entanglement is created for bosons than for their
fermion counterparts.Comment: revtex 4, 12 pages, 10 figures. Added Journal ref
Conformal invariance and apparent universality of semiclassical gravity
In a recent work, it has been pointed out that certain observables of the
massless scalar field theory in a static spherically symmetric background
exhibit a universal behavior at large distances. More precisely, it was shown
that, unlike what happens in the case the coupling to the curvature \xi is
generic, for the special cases \xi=0 and \xi = 1/6 the large distance behavior
of the expectation value turns out to be independent of the
internal structure of the gravitational source. Here, we address a higher
dimensional generalization of this result: We first compute the difference
between a black hole and a static spherically symmetric star for the
observables and in the far field limit. Thus, we show
that the conformally invariant massless scalar field theory in a static
spherically symmetric background exhibits such universality phenomenon in D\geq
4 dimensions. Also, using the one-loop effective action, we compute
for a weakly gravitating object. These results lead to the
explicit expression of the expectation value for a
Schwarzschild-Tangherlini black hole in the far field limit. As an application,
we obtain quantum corrections to the gravitational potential in D dimensions,
which for D=4 are shown to agree with the one-loop correction to the graviton
propagator previously found in the literature.Comment: 11 page
Hawking radiation from "phase horizons" in laser filaments?
Belgiorno et al have reported on experiments aiming at the detection of (the
analogue of) Hawking radiation using laser filaments [F. Belgiorno et al, Phys.
Rev. Lett. 105, 203901 (2010)]. They sent intense focused Bessel pulses into a
non-linear dielectric medium in order to change its refractive index via the
Kerr effect and saw creation of photons orthogonal to the direction of travel
of the pluses. Since the refractive index change in the pulse generated a
"phase horizon" (where the phase velocity of these photons equals the pulse
speed), they concluded that they observed the analogue of Hawking radiation. We
study this scenario in a model with a phase horizon and a phase velocity very
similar to that of their experiment and find that the effective metric does not
quite correspond to a black hole. The photons created in this model are not due
to the analogue of black hole evaporation but have more similarities to
cosmological particle creation. Nevertheless, even this effect cannot explain
the observations -- unless the pulse has significant small scale structure in
both the longitudinal and transverse dimensions.Comment: 13 pages RevTeX, 2 figure
Hawking Radiation from Fluctuating Black Holes
Classically, black Holes have the rigid event horizon. However, quantum
mechanically, the event horizon of black holes becomes fuzzy due to quantum
fluctuations. We study Hawking radiation of a real scalar field from a
fluctuating black hole. To quantize metric perturbations, we derive the
quadratic action for those in the black hole background. Then, we calculate the
cubic interaction terms in the action for the scalar field. Using these
results, we obtain the spectrum of Hawking radiation in the presence of
interaction between the scalar field and the metric. It turns out that the
spectrum deviates from the Planck spectrum due to quantum fluctuations of the
metric.Comment: 35pages, 4 figure
Detecting many-body entanglements in noninteracting ultracold atomic fermi gases
We explore the possibility of detecting many-body entanglement using
time-of-flight (TOF) momentum correlations in ultracold atomic fermi gases. In
analogy to the vacuum correlations responsible for Bekenstein-Hawking black
hole entropy, a partitioned atomic gas will exhibit particle-hole correlations
responsible for entanglement entropy. The signature of these momentum
correlations might be detected by a sensitive TOF type experiment.Comment: 5 pages, 5 figures, fixed axes labels on figs. 3 and 5, added
reference
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