598 research outputs found

    CreaSenses: fostering creativity through olfactory cues

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    Smell is a strong trigger of memories and creativity. Different smells can create sensitive environments that can foster creative tasks. In this paper, we present CreaSenses, a study that includes olfactory cues, representing different types of sensitive environ ments such as “food” and “ambience” in a within-subject design. Our aim was to obtain a deeper understanding of which smell cues promote higher levels of creativity during the process of creative writing. We discuss the results in the light of creative senses and potential implications for the design of creativity support tools. In addition, our study was evaluated trough the Creativity Support Index.info:eu-repo/semantics/publishedVersio

    de Sitter special relativity

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    A special relativity based on the de Sitter group is introduced, which is the theory that might hold up in the presence of a non-vanishing cosmological constant. Like ordinary special relativity, it retains the quotient character of spacetime, and a notion of homogeneity. As a consequence, the underlying spacetime will be a de Sitter spacetime, whose associated kinematics will differ from that of ordinary special relativity. The corresponding modified notions of energy and momentum are obtained, and the exact relationship between them, which is invariant under a re-scaling of the involved quantities, explicitly exhibited. Since the de Sitter group can be considered a particular deformation of the Poincar\'e group, this theory turns out to be a specific kind of deformed (or doubly) special relativity. Some experimental consequences, as well as the causal structure of spacetime--modified by the presence of the de Sitter horizon--are briefly discussed.Comment: V2: Some presentation changes; a new section introduced, with a discussion about possible phenomenological consequences; new references added; version to be published in Classical and Quantum Gravit

    On the equivalence principle and gravitational and inertial mass relation of classical charged particles

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    We show that the locally constant force necessary to get a stable hyperbolic motion regime for classical charged point particles, actually, is a combination of an applied external force and of the electromagnetic radiation reaction force. It implies, as the strong Equivalence Principle is valid, that the passive gravitational mass of a charged point particle should be slight greater than its inertial mass. An interesting new feature that emerges from the unexpected behavior of the gravitational and inertial mass relation, for classical charged particles, at very strong gravitational field, is the existence of a critical, particle dependent, gravitational field value that signs the validity domain of the strong Equivalence Principle. For electron and proton, these critical field values are gc4.8×1031m/s2g_{c}\simeq 4.8\times 10^{31}m/s^{2} and gc8.8×1034m/s2g_{c}\simeq 8.8\times 10^{34}m/s^{2}, respectively

    From wormhole to time machine: Comments on Hawking's Chronology Protection Conjecture

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    The recent interest in ``time machines'' has been largely fueled by the apparent ease with which such systems may be formed in general relativity, given relatively benign initial conditions such as the existence of traversable wormholes or of infinite cosmic strings. This rather disturbing state of affairs has led Hawking to formulate his Chronology Protection Conjecture, whereby the formation of ``time machines'' is forbidden. This paper will use several simple examples to argue that the universe appears to exhibit a ``defense in depth'' strategy in this regard. For appropriate parameter regimes Casimir effects, wormhole disruption effects, and gravitational back reaction effects all contribute to the fight against time travel. Particular attention is paid to the role of the quantum gravity cutoff. For the class of model problems considered it is shown that the gravitational back reaction becomes large before the Planck scale quantum gravity cutoff is reached, thus supporting Hawking's conjecture.Comment: 43 pages,ReV_TeX,major revision

    Wide-angle elastic scattering and color randomization

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    Baryon-baryon elastic scattering is considered in the independent scattering (Landshoff) mechanism. It is suggested that for scattering at moderate energies, direct and interchange quark channels contribute with equal color coefficients because the quark color is randomized by soft gluon exchange during the hadronization stage. With this assumption, it is shown that the ratio of cross sections Rpp/ppR_{\overline{p} p/ p p} at CM angle θ=900\theta = 90^0 decreases from a high energy value of R_{\pbar p / pp} \approx 1/2.7, down to R_{\pbar p / pp} \approx 1/28, compatible with experimental data at moderate energies. This sizable fall in the ratio seems to be characteristic of the Landshoff mechanism, in which changes at the quark level have a strong effect precisely because the hadronic process occurs via multiple quark scatterings. The effect of color randomization on the angular distribution of proton-proton elastic scattering and the cross section ratio Rnp/ppR_{np/pp} is also discussed.Comment: 18 pages, latex2e, 4 uuencoded figures, include

    On the K^+D Interaction at Low Energies

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    The Kd reactions are considered in the impulse approximation with NN final-state interactions (NN FSI) taken into account. The realistic parameters for the KN phase shifts are used. The "quasi-elastic" energy region, in which the elementary KN interaction is predominantly elastic, is considered. The theoretical predictions are compared with the data on the K^+d->K^+pn, K^+d->K^0pp, K^+d->K^+d and K^+d total cross sections. The NN FSI effect in the reaction K^+d->K^+pn has been found to be large. The predictions for the Kd cross sections are also given for slow kaons, produced from phi(1020) decays, as the functions of the isoscalar KN scattering length a_0. These predictions can be used to extract the value of a_0 from the data.Comment: 22 pages, 5 figure

    Bags, junctions, and networks of BPS and non-BPS defects

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    We investigate several models of coupled scalar fields that present discrete Z_2, Z_2 x Z_2, Z_3 and other symmetries. These models support topological domain wall solutions of the BPS and non-BPS type. The BPS solutions are stable, but the stability of the non-BPS solutions may depend on the parameters that specify the models. The BPS and non-BPS states give rise to bags, and also to three-junctions that may allow the presence of networks of topological defects. In particular, we show that the non-BPS defects of a specific model that engenders the Z_3 symmetry give rise to a stable regular hexagonal network of domain walls.Comment: Revtex, 16 pages, 6 ps figures; Shorter version to be published in Phys. Rev.

    The FeH Wing-Ford Band in Spectra of M Stars

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    We study the FeH Wing-Ford band at 9850 - 10200 Angstrons by means of the fit of synthetic spectra to the observations of M stars, employing recent model atmospheres. On the basis of the spectrum synthesis, we analyze the dependence of the band upon atmospheric parameters. FeH lines are a very sensitive surface gravity indicator, being stronger in dwarfs. They are also sensitive to metallicity (Allard & Hauschildt 1995). The blending with CN lines, which are stronger in giants, does not affect the response of the Wing-Ford band to surface gravity at low resolution (or high velocity dispersions) because CN lines, which are spread all along the spectrum, are smeared out at convolutions of FWHM \simgreat 3 Angstrons. We conclude that the Wing-Ford band is a suitable dwarf/giant indicator for the study of composite stellar populations.Comment: 23 pages + 11 figures in postscript format + 3 ps figures (Nos. 2, 6 and 7) available under request to [email protected]. Accepted for publication in The Astrophysical Journa

    Sum Rule Description of Color Transparency

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    The assumption that a small point-like configuration does not interact with nucleons leads to a new set of sum rules that are interpreted as models of the baryon-nucleon interaction. These models are rendered semi-realistic by requiring consistency with data for cross section fluctuations in proton-proton diffractive collisions.Comment: 22 pages + 3 postscript figures attache

    Neutron star in presence of torsion-dilaton field

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    We develop the general theory of stars in Saa's model of gravity with propagating torsion and study the basic stationary state of neutron star. Our numerical results show that the torsion force decreases the role of the gravity in the star configuration leading to significant changes in the neutron star masses depending on the equation of state of star matter. The inconsistency of the Saa's model with Roll-Krotkov-Dicke and Braginsky-Panov experiments is discussed.Comment: 29 pages, latex, 24 figures, final version. Added: 1)comments on different possible mass definitions; 2)new sections: a)the inconsistency of the Saa's model with Roll-Krotkov-Dicke and Braginsky-Panov experiments; b)stability analysis via catastrophe theory; 3)new figers added and some figures replaced. 4)new reference
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