598 research outputs found
CreaSenses: fostering creativity through olfactory cues
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
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
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
and , respectively
From wormhole to time machine: Comments on Hawking's Chronology Protection Conjecture
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
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 at CM angle
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 is also discussed.Comment: 18 pages, latex2e, 4 uuencoded figures, include
On the K^+D Interaction at Low Energies
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
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
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
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
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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