40,642 research outputs found

    William James and the Evolution of Consciousness

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    Despite having been relegated to the realm of superstition during the dominant years of behaviourism, the investigation and discussion of consciousness has again become scientifically defensible. However, attempts at describing animal consciousness continue to be criticised for lacking independent criteria that identify the presence or absence of the phenomenon. Over one hundred years ago William James recognised that mental traits are subject to the same evolutionary processes as are physical characteristics and must therefore be represented in differing levels of complexity throughout the animal kingdom. James's proposals with regard to animal consciousness are outlined and followed by a discussion of three classes of animal consciousness derived from empirical research. These classes are presented to defend both James's proposals and the position that a theory of animal consciousness can be scientifically supported. It is argued that by using particular behavioural expressions to index consciousness and by providing empirical tests by which to elicit these behavioural expressions a scientifically defensible theory of animal consciousness can be developed

    Collective Fields for QCD

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    A gauge-symmetric approach to effective Lagrangians is described with special emphasis on derivations of effective low-energy Lagrangians from QCD. The examples we discuss are based on exact rewritings of cut-off QCD in terms of new collective degrees of freedom. These cut-off Lagrangians are thus ``effective'' in the sense that they explicitly contain some of the physical long-distance degrees of freedom from the outset.(Talk presented by P.H. Damgaard at the workshop on ``Quantum Field Theoretical Methods in High Energy Physics'', Kyffhauser, Germany, Sept. 1993. To appear in those proceedings).Comment: LaTeX, 12 pages, CERN--TH-7035/9

    The lifetime cost of a magnetic refrigerator

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    The total cost of a 25 W average load magnetic refrigerator using commercial grade Gd is calculated using a numerical model. The price of magnetocaloric material, magnet material and cost of operation are considered, and all influence the total cost. The lowest combined total cost with a device lifetime of 15 years is found to be in the range \150$400dependingonthepriceofthemagnetocaloricandmagnetmaterial.Thecostofthemagnetislargest,followedcloselybythecostofoperation,whilethecostofthemagnetocaloricmaterialisalmostnegligible.Forthelowestcostdevice,theoptimalmagneticfieldisabout1.4T,theparticlesizeis0.23mm,thelengthoftheregeneratoris4050mmandtheutilizationisabout0.2,foralldevicelifetimesandmaterialandmagnetprices,whiletheoperatingfrequencyvaryasfunctionofdevicelifetime.TheconsideredperformancecharacteristicsarebasedontheperformanceofaconventionalA150-\$400 depending on the price of the magnetocaloric and magnet material. The cost of the magnet is largest, followed closely by the cost of operation, while the cost of the magnetocaloric material is almost negligible. For the lowest cost device, the optimal magnetic field is about 1.4 T, the particle size is 0.23 mm, the length of the regenerator is 40-50 mm and the utilization is about 0.2, for all device lifetimes and material and magnet prices, while the operating frequency vary as function of device lifetime. The considered performance characteristics are based on the performance of a conventional A^{+++}$ refrigeration unit. In a rough life time cost comparison between the magnetic refrigeration device and such a unit we find similar costs, the former being slightly cheaper, assuming the cost of the magnet can be recuperated at end of life.Comment: 17 pages, 17 figure

    On the smallness of the cosmological constant in SUGRA models

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    In no--scale supergravity global symmetries protect local supersymmetry and a zero value for the cosmological constant. We consider the breakdown of these symmetries and present a minimal SUGRA model motivated by the multiple point principle, in which the total vacuum energy density is naturally tiny. In order to reproduce the observed value of the cosmological constant and preserve gauge coupling unification, an additional pair of 5+5ˉ5+\bar{5}--plets of superfields has to be included in the particle content of the considered model. These extra fields have masses of the order of the supersymmetry breaking scale; so they can be detected at future colliders. We also discuss the supersymmetry breakdown and possible solution of the cosmological constant problem by MPP in models with an enlarged gauge symmetry.Comment: 28 pages, 3 figures, some minor changes to the text, references adde

    Gravitational Lorentz anomaly from the overlap formula in 2-dimensions

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    In this letter we show that the overlap formulation of chiral gauge theories correctly reproduces the gravitational Lorentz anomaly in 2-dimensions. This formulation has been recently suggested as a solution to the fermion doubling problem on the lattice. The well known response to general coordinate transformations of the effective action of Weyl fermions coupled to gravity in 2-dimensions can also be recovered.Comment: 7 pages, late

    Multiple point principle as a mechanism for the suppression of FCNC and CP--violation phenomena in the 2HDM

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    We argue that multiple point principle (MPP) can be used to ensure CP conservation and the absence of flavour changing neutral currents within the two Higgs doublet model (2HDM). We also discuss Higgs phenomenology in the MPP inspired 2HDM.Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 2 eps figures,CERN preprint number added, references update

    On the Smallness of the Cosmological Constant in SUGRA Models Inspired by Degenerate Vacua

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    In the no-scale supergravity global symmetries protect local supersymmetry and a zero value for the cosmological constant. The breakdown of these symmetries, which ensures the vanishing of the vacuum energy density, results in a set of degenerate vacua with broken and unbroken supersymmetry leading to the natural realisation of the multiple point principle (MPP). In the MPP inspired SUGRA models the cosmological constant is naturally tiny.Comment: Parallel talk at SUSY09, Boston, USA, June 2009, 5 page

    Why Nature has made a choice of one time and three space coordinates?

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    We propose a possible answer to one of the most exciting open questions in physics and cosmology, that is the question why we seem to experience four- dimensional space-time with three ordinary and one time dimensions. We have known for more than 70 years that (elementary) particles have spin degrees of freedom, we also know that besides spin they also have charge degrees of freedom, both degrees of freedom in addition to the position and momentum degrees of freedom. We may call these ''internal degrees of freedom '' the ''internal space'' and we can think of all the different particles, like quarks and leptons, as being different internal states of the same particle. The question then naturally arises: Is the choice of the Minkowski metric and the four-dimensional space-time influenced by the ''internal space''? Making assumptions (such as particles being in first approximation massless) about the equations of motion, we argue for restrictions on the number of space and time dimensions. (Actually the Standard model predicts and experiments confirm that elementary particles are massless until interactions switch on masses.) Accepting our explanation of the space-time signature and the number of dimensions would be a point supporting (further) the importance of the ''internal space''.Comment: 13 pages, LaTe
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