3,311 research outputs found
The Intermediate Coupling Regime in the AdS/CFT Correspondence
The correspondence between the 't Hooft limit of N=4 super Yang-Mills theory
and tree-level IIB superstring theory on AdS(5)xS(5) in a Ramond-Ramond
background at values of lambda=g^2 N ranging from infinity to zero is examined
in the context of unitarity. A squaring relation for the imaginary part of the
holographic scattering of identical string fields in the two-particle channels
is found, and a mismatch between weak and strong 't Hooft coupling is pointed
out within the correspondence. Several interpretations and implications are
proposed.Comment: 10 pages, LaTeX, reference adde
Dynamical density functional theory for the evaporation of droplets of nanoparticle suspension
We develop a lattice gas model for the drying of droplets of a nanoparticle
suspension on a planar surface, using dynamical density functional theory
(DDFT) to describe the time evolution of the solvent and nanoparticle density
profiles. The DDFT assumes a diffusive dynamics but does not include the
advective hydrodynamics of the solvent, so the model is relevant to highly
viscous or near to equilibrium systems. Nonetheless, we see an equivalent of
the coffee-ring stain effect, but in the present model it occurs for
thermodynamic rather the fluid-mechanical reasons. The model incorporates the
effect of phase separation and vertical density variations within the droplet
and the consequence of these on the nanoparticle deposition pattern on the
surface. We show how to include the effect of slip or no-slip at the surface
and how this is related to the receding contact angle. We also determine how
the equilibrium contact angle depends on the microscopic interaction
parameters.Comment: 35 pages, 10 figure
Simplifying Algebra in Feynman Graphs, Part III: Massive Vectors
A T-dualized selfdual inspired formulation of massive vector fields coupled
to arbitrary matter is generated; subsequently its perturbative series modeling
a spontaneously broken gauge theory is analyzed. The new Feynman rules and
external line factors are chirally minimized in the sense that only one type of
spin index occurs in the rules. Several processes are examined in detail and
the cross-sections formulated in this approach. A double line formulation of
the Lorentz algebra for Feynman diagrams is produced in this formalism, similar
to color ordering, which follows from a spin ordering of the Feynman rules. The
new double line formalism leads to further minimization of gauge invariant
scattering in perturbation theory. The dualized electroweak model is also
generated.Comment: 39 pages, LaTeX, 8 figure
Using administrative data to look at changes in the level and distribution of out-of-pocket medical expenditure: An example using Medicare data from Australia.
OBJECTIVES: Australia's universal health insurance system Medicare generates very large amounts of data on out-of-pocket expenditure (OOPE), but only highly aggregated statistics are routinely published. Our primary purpose is to develop indices from the Medicare administrative data to quantify changes in the level and distribution of OOPE on out-of-hospital medical services over time. METHODS: Data were obtained from the Australian Hypertension and Absolute Risk Study, which involved patients aged 55 years and over (n=2653). Socio-economic and clinical information was collected and linked to Medicare records over a five-year period from March 2008. The Fisher price and quantity indices were used to evaluate year-to-year changes in OOPE. The relative concentration index was used to evaluate the distribution of OOPE across socio-economic strata. RESULTS: Our price index indicates that overall OOPE were not rising faster than inflation, but there was considerable variation across different types of services (e.g. OOPE on professional attendances rose by 20% over a five-year period, while all other items fell by around 14%). Concentration indices, adjusted for demographic factors and clinical need, indicate that OOPE tends to be higher among those on higher incomes. CONCLUSIONS: A major challenge in utilizing large administrative data sets is to develop reliable and easily interpretable statistics for policy makers. Price, quantity and concentration indices represent statistics that move us beyond the average
Hidden Symmetries of the Open N=2 String
It is known for ten years that self-dual Yang-Mills theory is the effective
field theory of the open N=2 string in 2+2 dimensional spacetime. We uncover an
infinite set of abelian rigid string symmetries, corresponding to the
symmetries and integrable hierarchy of the self-dual Yang-Mills equations. The
twistor description of the latter naturally connects with the BRST approach to
string quantization, providing an interpretation of the picture phenomenon in
terms of the moduli space of string backgrounds.Comment: 24 pages, no figures; v2: typos correcte
Doing science: how to get credit for your scientific work.
Everyone deserves to be acknowledged for their efforts and contributions to a shared goal, and getting credit for your scientific work should be part of a natural process and should be fair and straightforward. However, credit cannot be objectively measured despite it having a big influence and, unfortunately, getting appropriate credit can occasionally be both complicated and challenging
Holographic Normal Ordering and Multi-particle States in the AdS/CFT Correspondence
The general correlator of composite operators of N=4 supersymmetric gauge
field theory is divergent. We introduce a means for renormalizing these
correlators by adding a boundary theory on the AdS space correcting for the
divergences. Such renormalizations are not equivalent to the standard normal
ordering of current algebras in two dimensions. The correlators contain contact
terms that contribute to the OPE; we relate them diagrammatically to
correlation functions of compound composite operators dual to multi-particle
states.Comment: 18 pages, one equation corr., further comments and refs. adde
The Real Combination Problem : Panpsychism, Micro-Subjects, and Emergence
Panpsychism harbors an unresolved tension, the seriousness of which has yet to be fully appreciated. I capture this tension as a dilemma, and offer panpsychists advice on how to resolve it. The dilemma, briefly, is as follows. Panpsychists are committed to the perspicuous explanation of macro-mentality in terms of micro-mentality. But panpsychists take the micro-material realm to feature not just mental properties, but also micro-subjects to whom these properties belong. Yet it is impossible to explain the constitution of a macro-subject (like one of us) in terms of the assembly of micro-subjects, for, I show, subjects cannot combine. Therefore the panpsychist explanatory project is derailed by the insistence that the worldâs ultimate material constituents (ultimates) are subjects of experience. The panpsychist faces a choice of abandoning her explanatory project, or recanting the claim that the ultimates are subjects. This is the dilemma. I argue that the latter option is to be preferred. This neednât constitute a wholesale abandonment of panpsychism, however, since panpsychists can maintain that the ultimates possess phenomenal qualities, despite not being subjects of those qualities. This proposal requires us to make sense of phenomenal qualities existing independently of experiencing subjects, a challenge I tackle in the penultimate section. The position eventually reached is a form of neutral monism, so another way to express the overall argument is to say that, keeping true to their philosophical motivations, panpsychists should really be neutral monists.Peer reviewedFinal Accepted Versio
Russellian Monism and Mental Causation
© 2019 Wiley Periodicals, Inc.According to Russellian monism, consciousness is constituted at least partly by quiddities: intrinsic properties that categorically ground dispositional properties described by fundamental physics. If the theory is true, then consciousness and such dispositional properties are closely connected. But how closely? The contingency thesis says that the connection is contingent. For example, on this thesis the dispositional property associated with negative charge might have been categorically grounded by a quiddity that is distinct from the one that actually grounds it. Some argue that Russellian monism entails the contingency thesis and that this makes its consciousnessâconstituting quiddities epiphenomenalâa disastrous outcome for a theory that is motivated partly by its prospects for integrating consciousness into physical causation. We consider two versions of that argument, a generic version and an intriguing version developed by Robert J. Howell, which he bases on Jaegwon Kim's wellâknown âexclusion argument.â We argue that neither succeeds.Peer reviewe
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