6,073 research outputs found
Non-perturbative QEG Corrections to the Yang-Mills Beta Function
We discuss the non-perturbative renormalization group evolution of the gauge
coupling constant by using a truncated form of the functional flow equation for
the effective average action of the Yang-Mills-gravity system. Our result is
consistent with the conjecture that Quantum Einstein Gravity (QEG) is
asymptotically safe and has a vanishing gauge coupling constant at the
non-trivial fixed point.Comment: To appear in the proceedings of CORFU 200
Growth, profits and technological choice: The case of the Lancashire cotton textile industry
Using Lancashire textile industry company case studies and financial records, mainly from the period just before the First World War, the processes of growth and decline are re-examined. These are considered by reference to the nature of Lancashire entrepreneurship and the impact on technological choice. Capital accumulation, associated wealth distributions and the character of Lancashire business organisation were sybiotically linked to the success of the industry before 1914. However, the legacy of that accumulation in later decades, chronic overcapacity, formed a barrier to reconstruction and enhanced the preciptious decline of a once great industry
Quantum corrections to Higher-Dimensional Theories
This is a non-technical summary of the subtleties of quantum corrections on
extra-dimensional theories: should one first renormalize and then mode expand,
or first expand in four-dimensional modes and then renormalize?Comment: 9 pages, based on a talk at IRGAC 2006, Barcelon
Comparison theory and smooth minimal C*-dynamics
We prove that the C*-algebra of a minimal diffeomorphism satisfies
Blackadar's Fundamental Comparability Property for positive elements. This
leads to the classification, in terms of K-theory and traces, of the
isomorphism classes of countably generated Hilbert modules over such algebras,
and to a similar classification for the closures of unitary orbits of
self-adjoint elements. We also obtain a structure theorem for the Cuntz
semigroup in this setting, and prove a conjecture of Blackadar and Handelman:
the lower semicontinuous dimension functions are weakly dense in the space of
all dimension functions. These results continue to hold in the broader setting
of unital simple ASH algebras with slow dimension growth and stable rank one.
Our main tool is a sharp bound on the radius of comparison of a recursive
subhomogeneous C*-algebra. This is also used to construct uncountably many
non-Morita-equivalent simple separable amenable C*-algebras with the same
K-theory and tracial state space, providing a C*-algebraic analogue of McDuff's
uncountable family of II_1 factors. We prove in passing that the range of the
radius of comparison is exhausted by simple C*-algebras.Comment: 30 pages, no figure
There is no new physics in the multiplicative anomaly
We discuss the role of the multiplicative anomaly for a complex scalar field
at finite temperature and density. It is argued that physical considerations
must be applied to determine which of the many possible expressions for the
effective action obtained by the functional integral method is correct. This is
done by first studying the non-relativistic field where the thermodynamic
potential is well-known. The relativistic case is also considered. We emphasize
that the role of the multiplicative anomaly is not to lead to new physics, but
rather to preserve the equality among the various expressions for the effective
action.Comment: 24 pages, RevTex, no figure
Locally Trivial W*-Bundles
We prove that a tracially continuous W-bundle over a
compact Hausdorff space with all fibres isomorphic to the hyperfinite
II-factor that is locally trivial already has to be globally
trivial. The proof uses the contractibility of the automorphism group
shown by Popa and Takesaki. There is no
restriction on the covering dimension of .Comment: 20 pages, this version will be published in the International Journal
of Mathematic
Delay of Disorder by Diluted Polymers
We study the effect of diluted flexible polymers on a disordered capillary
wave state. The waves are generated at an interface of a dyed water sugar
solution and a low viscous silicon oil. This allows for a quantitative
measurement of the spatio-temporal Fourier spectrum. The primary pattern after
the first bifurcation from the flat interface are squares. With increasing
driving strength we observe a melting of the square pattern. It is replaced by
a weak turbulent cascade. The addition of a small amount of polymers to the
water layer does not affect the critical acceleration but shifts the disorder
transition to higher driving strenghs and the short wave length - high
frequency fluctuations are suppressed
Piloting a digitally-mediated social story intervention for autistic children led by teachers within naturalistic school settings
BackgroundSocial stories (SS) are widely used within the autism community. However, research into their effectiveness is mixed at best and mainly relies on single case study designs. Additional support from the researcher is also often provided, raising questions as to the use and effectiveness of SS within usual school settings.MethodSeventeen school teachers developed and delivered personalised digitally-mediated SS with 22 autistic children (aged 5-11yrs) over a 4-week intervention period. Data was collected during a baseline period (1 week), throughout the 4-week intervention phase and at 6-week follow-up to consider changes in child behaviour, understanding and anxiety. A new assessment framework to evaluation treatment fidelity according to Grayâs 10 Criteria was also developed.ResultsWith the support of a new SS app teachers were able to carry out SS interventions with a high degree of fidelity within their usual school settings. Behavioural data showed significant improvements from baseline to week 4 for all measures relating to the goals of the intervention (including a reduction in anxiety and an increase in understanding), some of which were still present at follow-up.ConclusionThis study has demonstrated that technology can be used to support teachers to develop and deliver SS interventions to autistic children within school settings. Such technology can now be used to facilitate much needed future, larger, controlled studies within this area. Implications for practice are discussed
Quantum gravitational contributions to quantum electrodynamics
Quantum electrodynamics describes the interactions of electrons and photons.
Electric charge (the gauge coupling constant) is energy dependent, and there is
a previous claim that charge is affected by gravity (described by general
relativity) with the implication that the charge is reduced at high energies.
But that claim has been very controversial with the situation inconclusive.
Here I report an analysis (free from earlier controversies) demonstrating that
that quantum gravity corrections to quantum electrodynamics have a quadratic
energy dependence that result in the reduction of the electric charge at high
energies, a result known as asymptotic freedom.Comment: To be published in Nature. 19 pages LaTeX, no figure
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Supplementary feeding of the reintroduced Red Kite (Milvus milvus) in UK gardens
Capsule The provision of meat for garden birds is unusual in the UK but a reintroduced raptor, the Red Kite Milvus milvus, is now regularly fed in some areas. A questionnaire of garden kite feeders revealed that people were most often motivated to feed by a desire to see kites close up and that most provisioning falls within available guidelines. We estimated the median amount of food thought to be taken by kites per kite-feeding garden per day as 21â
g, sufficient to support 0.12â0.26 individuals
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