829 research outputs found
Mild place illusion: a virtual reality factor to spark creativity in writing
Developments in Virtual Reality (VR) technology have modified
the creative potential of each individual. We introduce a new con cept, called "mild place illusion", as a new paradigm for designing
VR-based user interfaces targeted at stimulating creativity. We
show that for creative tasks - such as creative writing, new product
ideation, and brainstorming - a "just-enough" amount of place illu sion leads to a greater self-perception of creativity, as opposed to a
"full-level" place illusion. This is a somewhat unexpected result
since one would suppose, a priori, to have the full-level place illu sion as the optimal setup for stimulating creativity. We considered
that the methodology in this work was fairly complex, but our re sults show – through a data triangulation approach – that we were
able to identify more consistent and personal creative experiences.
Therefore, the main contribution of this paper is a new paradigm
for designing VR user interfaces targeted at stimulating creativity
by showing that a “one-illusion interspace” leads to a greater self perception of creativity.info:eu-repo/semantics/publishedVersio
Metric of a tidally perturbed spinning black hole
We explicitly construct the metric of a Kerr black hole that is tidally
perturbed by the external universe in the slow-motion approximation. This
approximation assumes that the external universe changes slowly relative to the
rotation rate of the hole, thus allowing the parameterization of the
Newman-Penrose scalar by time-dependent electric and magnetic tidal
tensors. This approximation, however, does not constrain how big the spin of
the background hole can be and, in principle, the perturbed metric can model
rapidly spinning holes. We first generate a potential by acting with a
differential operator on . From this potential we arrive at the metric
perturbation by use of the Chrzanowski procedure in the ingoing radiation
gauge. We provide explicit analytic formulae for this metric perturbation in
spherical Kerr-Schild coordinates, where the perturbation is finite at the
horizon. This perturbation is parametrized by the mass and Kerr spin parameter
of the background hole together with the electric and magnetic tidal tensors
that describe the time evolution of the perturbation produced by the external
universe. In order to take the metric accurate far away from the hole, these
tidal tensors should be determined by asymptotically matching this metric to
another one valid far from the hole. The tidally perturbed metric constructed
here could be useful in initial data constructions to describe the metric near
the horizons of a binary system of spinning holes. This perturbed metric could
also be used to construct waveforms and study the absorption of mass and
angular momentum by a Kerr black hole when external processes generate
gravitational radiation.Comment: 17 pages, 3 figures. Final PRD version, minor typos, etc corrected.
v3: corrected typo in Eq. (35) and (57
Self Interacting Dark Matter in the Solar System
Weakly coupled, almost massless, spin 0 particles have been predicted by many
extensions of the standard model of particle physics. Recently, the PVLAS group
observed a rotation of polarization of electromagnetic waves in vacuum in the
presence of transverse magnetic field. This phenomenon is best explained by the
existence of a weakly coupled light pseudoscalar particle. However, the
coupling required by this experiment is much larger than the conventional
astrophysical limits. Here we consider a hypothetical self-interacting
pseudoscalar particle which couples weakly with visible matter.
Assuming that these pseudoscalars pervade the galaxy, we show that the solar
limits on the pseudoscalar-photon coupling can be evaded.Comment: 17 pages, 2 figure
Invasive Streptococcus pneumoniae in Children, Malawi, 2004–2006
Of 176 invasive Streptococcus pneumoniae isolates from children in Malawi, common serotypes were 1 (23%), 6A/B (18%), 14 (6%), and 23F (6%). Coverage with the 7-valent pneumococcal conjugate vaccine (PCV) was 39%; PCV10 and PCV13 increased coverage to 66% and 88%, respectively. We found chloramphenicol resistance in 27% of isolates and penicillin nonsusceptibility in 10% (by using meningitis breakpoints); all were ceftriaxone susceptible
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
Exploring the vicinity of the Bogomol'nyi-Prasad-Sommerfield bound
We investigate systems of real scalar fields in bidimensional spacetime,
dealing with potentials that are small modifications of potentials that admit
supersymmetric extensions. The modifications are controlled by a real
parameter, which allows implementing a perturbation procedure when such
parameter is small. The approach allows obtaining the energy and topological
charge in closed forms, up to first order in the parameter. We illustrate the
procedure with some examples. In particular, we show how to remove the
degeneracy in energy for the one-field and the two-field solutions that appear
in a model of two real scalar fields.Comment: Revtex, 9 pages, To be published in J. Phys.
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
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
Gravitational collapse in asymptotically Anti-de Sitter/de Sitter backgrounds
We study here the gravitational collapse of a matter cloud with a
non-vanishing tangential pressure in the presence of a non-zero cosmological
term. Conditions for bounce and singularity formation are derived for the
model. It is also shown that when the tangential pressures vanish, the bounce
and singularity conditions reduce to that of the dust case studied earlier. The
collapsing interior is matched with an exterior which is asymptotically de
Sitter or anti de Sitter, depending on the sign of cosmological constant. The
junction conditions for matching the cloud to exterior are specified. The
effect of the cosmological term on apparent horizons is studied in some detail,
and the nature of central singularity is analyzed. We also discuss here the
visibility of the singularity and implications for the cosmic censorship
conjecture.Comment: 11 pages, 1 figure, Revtex
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