3,472 research outputs found
Regular black holes in an asymptotically de Sitter universe
A regular solution of the system of coupled equations of the nonlinear
electrodynamics and gravity describing static and spherically-symmetric black
holes in an asymptotically de Sitter universe is constructed and analyzed.
Special emphasis is put on the degenerate configurations (when at least two
horizons coincide) and their near horizon geometry. It is explicitly
demonstrated that approximating the metric potentials in the region between the
horizons by simple functions and making use of a limiting procedure one obtains
the solutions constructed from maximally symmetric subspaces with different
absolute values of radii. Topologically they are for the
cold black hole, when the event and cosmological horizon
coincide, and the Pleba\'nski- Hacyan solution for the ultraextremal black
hole. A physically interesting solution describing the lukewarm black holes is
briefly analyze
Schumpeterian economic dynamics as a quantifiable minimum model of evolution
We propose a simple quantitative model of Schumpeterian economic dynamics.
New goods and services are endogenously produced through combinations of
existing goods. As soon as new goods enter the market they may compete against
already existing goods, in other words new products can have destructive
effects on existing goods. As a result of this competition mechanism existing
goods may be driven out from the market - often causing cascades of secondary
defects (Schumpeterian gales of destruction). The model leads to a generic
dynamics characterized by phases of relative economic stability followed by
phases of massive restructuring of markets - which could be interpreted as
Schumpeterian business `cycles'. Model timeseries of product diversity and
productivity reproduce several stylized facts of economics timeseries on long
timescales such as GDP or business failures, including non-Gaussian fat tailed
distributions, volatility clustering etc. The model is phrased in an open,
non-equilibrium setup which can be understood as a self organized critical
system. Its diversity dynamics can be understood by the time-varying topology
of the active production networks.Comment: 21 pages, 11 figure
Sublingual allergen immunotherapy with a liquid birch pollen product in patients with seasonal allergic rhinoconjunctivitis with or without asthma
Background: Sublingual allergen immunotherapy (SLIT) has been demonstrated to be both clinically efficacious and safe. However, in line with the current regulatory guidance from the European Medicines Agency, allergen immunotherapy (AIT) products must demonstrate their efficacy and safety in pivotal phase III trials for registration.
Objective: We sought to investigate the efficacy and safety of sublingual high-dose liquid birch pollen extract (40,000 allergy units native [AUN]/mL) in adults with birch pollen allergy.
Methods: A randomized, double-blind, placebo-controlled, parallel-group multicenter trial was conducted in 406 adult patients with moderate-to-severe birch pollen-induced allergic rhinoconjunctivitis with or without mild-to-moderate controlled asthma. Treatment was started 3 to 6 months before the birch pollen season and continued during the season in 40 clinical study centers in 5 European countries. For primary end point assessment, the recommended combined symptom and medication score of the European Academy of Allergy and Clinical Immunology was used. Secondary end points included quality-of-life assessments, immunologic parameters, and safety.
Results: Primary efficacy results demonstrated a significant (P < .0001) and clinically relevant (32%) reduction in the combined symptom and medication score compared with placebo after 3 to 6 months of SLIT. Significantly better rhinoconjunctivitis quality-of-life scores (P < .0001) and the patient's own overall assessment of his or her health status, including the visual analog scale score (Euro Quality of Life Visual Analogue Scale; P = .0025), were also demonstrated. In total, a good safety profile of SLIT was observed.
Conclusion: This study confirmed both the clinical efficacy and safety of a sublingual liquid birch pollen extract in adults with birch pollen allergy in a pivotal phase III trial (EudraCT: 2013-005550-30; ClinicalTrials. gov: NCT02231307)
Convergence and multiplicities for the Lempert function
Given a domain , the Lempert function is a
functional on the space Hol (\D,\Omega) of analytic disks with values in
, depending on a set of poles in . We generalize its definition
to the case where poles have multiplicities given by local indicators (in the
sense of Rashkovskii's work) to obtain a function which still dominates the
corresponding Green function, behaves relatively well under limits, and is
monotonic with respect to the indicators. In particular, this is an improvement
over the previous generalization used by the same authors to find an example of
a set of poles in the bidisk so that the (usual) Green and Lempert functions
differ.Comment: 24 pages; many typos corrected thanks to the referee of Arkiv for
Matemati
Logical independence and quantum randomness
We propose a link between logical independence and quantum physics. We
demonstrate that quantum systems in the eigenstates of Pauli group operators
are capable of encoding mathematical axioms and show that Pauli group quantum
measurements are capable of revealing whether or not a given proposition is
logically dependent on the axiomatic system. Whenever a mathematical
proposition is logically independent of the axioms encoded in the measured
state, the measurement associated with the proposition gives random outcomes.
This allows for an experimental test of logical independence. Conversely, it
also allows for an explanation of the probabilities of random outcomes observed
in Pauli group measurements from logical independence without invoking quantum
theory. The axiomatic systems we study can be completed and are therefore not
subject to Goedel's incompleteness theorem.Comment: 9 pages, 4 figures, published version plus additional experimental
appendi
Bianchi Type I Magnetofluid Cosmological Models with Variable Cosmological Constant Revisited
The behaviour of magnetic field in anisotropic Bianchi type I cosmological
model for bulk viscous distribution is investigated. The distribution consists
of an electrically neutral viscous fluid with an infinite electrical
conductivity. It is assumed that the component of shear tensor
is proportional to expansion () and the coefficient of
bulk viscosity is assumed to be a power function of mass density. Some physical
and geometrical aspects of the models are also discussed in presence and also
in absence of the magnetic field.Comment: 13 page
Polynomial diffeomorphisms of C^2, IV: The measure of maximal entropy and laminar currents
This paper concerns the dynamics of polynomial automorphisms of .
One can associate to such an automorphism two currents and the
equilibrium measure . In this paper we study some
geometric and dynamical properties of these objects. First, we characterize
as the unique measure of maximal entropy. Then we show that the measure
has a local product structure and that the currents have a
laminar structure. This allows us to deduce information about periodic points
and heteroclinic intersections. For example, we prove that the support of
coincides with the closure of the set of saddle points. The methods used
combine the pluripotential theory with the theory of non-uniformly hyperbolic
dynamical systems
Can a matter-dominated model with constant bulk viscosity drive the accelerated expansion of the universe?
We test a cosmological model which the only component is a pressureless fluid
with a constant bulk viscosity as an explanation for the present accelerated
expansion of the universe. We classify all the possible scenarios for the
universe predicted by the model according to their past, present and future
evolution and we test its viability performing a Bayesian statistical analysis
using the SCP ``Union'' data set (307 SNe Ia), imposing the second law of
thermodynamics on the dimensionless constant bulk viscous coefficient \zeta and
comparing the predicted age of the universe by the model with the constraints
coming from the oldest globular clusters.
The best estimated values found for \zeta and the Hubble constant Ho are:
\zeta=1.922 \pm 0.089 and Ho=69.62 \pm 0.59 km/s/Mpc with a \chi^2=314. The age
of the universe is found to be 14.95 \pm 0.42 Gyr. We see that the estimated
value of Ho as well as of \chi^2 are very similar to those obtained from LCDM
model using the same SNe Ia data set. The estimated age of the universe is in
agreement with the constraints coming from the oldest globular clusters.
Moreover, the estimated value of \zeta is positive in agreement with the second
law of thermodynamics (SLT).
On the other hand, we perform different forms of marginalization over the
parameter Ho in order to study the sensibility of the results to the way how Ho
is marginalized. We found that it is almost negligible the dependence between
the best estimated values of the free parameters of this model and the way how
Ho is marginalized in the present work. Therefore, this simple model might be a
viable candidate to explain the present acceleration in the expansion of the
universe.Comment: 31 pages, 12 figures and 2 tables. Accepted to be published in the
Journal of Cosmology and Astroparticle Physics. Analysis using the new SCP
"Union" SNe Ia dataset instead of the Gold 2006 and ESSENCE datasets and
without changes in the conclusions. Added references. Related works:
arXiv:0801.1686 and arXiv:0810.030
Constant Curvature Coefficients and Exact Solutions in Fractional Gravity and Geometric Mechanics
We study fractional configurations in gravity theories and Lagrange
mechanics. The approach is based on Caputo fractional derivative which gives
zero for actions on constants. We elaborate fractional geometric models of
physical interactions and we formulate a method of nonholonomic deformations to
other types of fractional derivatives. The main result of this paper consists
in a proof that for corresponding classes of nonholonomic distributions a large
class of physical theories are modelled as nonholonomic manifolds with constant
matrix curvature. This allows us to encode the fractional dynamics of
interactions and constraints into the geometry of curve flows and solitonic
hierarchies.Comment: latex2e, 11pt, 27 pages, the variant accepted to CEJP; added and
up-dated reference
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