1,770 research outputs found
Reply to the "Comment on 'Piezonuclear decay of thorium' [Phys. Lett. A 373 (2009) 1956]" [Phys. Lett. A 373 (2009) 3795] by G. Ericsson et al
In a paper appearing in this issue of Physics Letters A, Ericsson et al.
raise some critical comments on the experiment [F. Cardone, R. Mignani, A.
Petrucci, Phys. Lett. A 373 (2009) 1956] we carried out by cavitating a
solution of thorium-228, which evidenced its anomalous decay behaviour, thus
confirming the results previously obtained by Urutskoev et al. by explosion of
titanium foils in solutions. In this Letter, we reply to these comments. In our
opinion, the main shortcomings of the criticism by the Swedish authors are due
to their omitting of inserting our experiment in the wider research stream of
piezonuclear reactions, and to the statistical analysis they used, which does
not comply with the rules generally accepted for samples with small numbers.
However, apart from any possible theoretical speculation, there is the basic
fact that two different experiments (ours and that by Urutskoev et al.),
carried out independently and by different means, highlight an analogous
anomaly in the decay of thorium subjected to pressure waves. Such a convergence
of results shows that it is worth to further carry on experimental
investigations, in order to get either a confirmation or a disproof of the
induced-pressure anomalous behaviour of radioactive nuclides even different
from thorium.Comment: 8 pages, 1 figur
Possible Experimental Evidence for Violation of Standard Electrodynamics, de Broglie Pilot Wave and Spacetime Deformation
We report and discuss the results of double-slit-like experiments in the
infrared range, which evidence an anomalous behaviour of photon systems under
particular (energy and space) constraints. These outcomes apparently disagree
both with standard quantum mechanics (Copenhagen interpretation) and with
classical and quantum electrodynamics. Possible interpretations can be given in
terms of either the existence of de Broglie-Bohm pilot waves associated to
photons, and/or the breakdown of local Lorentz invariance (LLI). We put forward
an intriguing hypothesis about the possible connection between these seemingly
unrelated points of view by assuming that the pilot wave of a photon is, in the
framework of LLI breakdown, a local deformation of the flat minkowskian
spacetime.Comment: 15 pages, 6 figures, presented at CASYS'09 - International Conference
on COMPUTING ANTICIPATORY SYSTEMS - HEC Management School - University of
Liege, LIEGE, Belgium, August 3-8, 2009. The paper was peer reviewed as
explicitely stated on page x in the AIP CONFERENCE PROCEEDINGS 1303 -
Computing Anticipatory Systems - CASYS'09 Ninth International Conference,
Li\`ege Belgium, August 3-8, 200
Geometrical Lorentz Violation and Quantum Mechanical Physics
On the basis of the results of some experiments dealing with the violation of
Local Lorentz Invariance (LLI) and on the formalism of the Deformed Special
Relativity (DSR), we examine the connections between the local geometrical
structure of space-time and the foundation of Quantum Mechanics. We show that
Quantum Mechanics, beside being an axiomatic theory, can be considered also a
deductive physical theory, deducted from the primary physical principle of
Relativistic Correlation. This principle is synonym of LLI and of a rigid and
at minkowskian space-time. The results of the experiments mentioned above show
the breakdown of LLI and hence the violation of the principle of Relativistic
Correlation. The formalism of DSR allows to highlight the deep meaning of LLI
breakdown in terms of the geometrical structure of local space-time which, far
from being rigid and at, is deformed by the energy of the physical phenomena
that take place and in this sense it has an active part in the dynamics of the
whole physical process. This perspective has a far reaching physical meaning
that extends its consequences to the foundations of Quantum Mechanics according
to the interpretation of Copenhagen. It provides a 'real' explanation and
description of quantum phenomena enriching, by the concept of deformed
space-time, the realistic interpretation in terms of pilot wave and hence it
uncovers the reality hidden below the probabilistic interpretation and
dualistic nature of quantum objects.Comment: 4 figures, 15 page
Hints for families of GRBs improving the Hubble diagram
As soon as their extragalactic origins were established, the hope to make
Gamma - Ray Bursts (GRBs) standardizeable candles to probe the very high - z
universe has opened the search for scaling relations between redshift
independent observable quantities and distance dependent ones. Although some
remarkable success has been achieved, the empirical correlations thus found are
still affected by a significant intrinsic scatter which downgrades the
precision in the inferred GRBs Hubble diagram. We investigate here whether this
scatter may come from fitting together objects belonging to intrinsically
different classes. To this end, we rely on a cladistics analysis to partition
GRBs in homogenous families according to their rest frame properties. Although
the poor statistics prevent us from drawing a definitive answer, we find that
both the intrinsic scatter and the coefficients of the \,-\,
and \,-\, correlations significantly change depending on which
subsample is fitted. It turns out that the fit to the full sample leads to a
scaling relation which approximately follows the diagonal of the region
delimited by the fits to each homogenous class. We therefore argue that a
preliminary identification of the class a GRB belongs to is necessary in order
to select the right scaling relation to be used in order to not bias the
distance determination and hence the Hubble diagram.Comment: 10 pages, 6 figures, 4 tables, accepted for publication on MNRA
Cosmological parameters from lenses distance ratio
Strong lensing provides popular techniques to investigate the mass
distribution of intermediate redshift galaxies, testing galaxy evolution and
formation scenarios. It especially probes the background cosmic expansion,
hence constraining cosmological parameters. The measurement of Einstein radii
and central velocity dispersions indeed allows to trace the ratio D_s/D_ls
between the distance D_s from the observer to the source and the distance D_ls
from the lens to the source. We present an improved method to explicitly
include the two - component structure in the galaxy lens modeling, in order to
analyze the role played by the redshift and the model dependence on a nuisance
parameter, F_E, which is usually marginalized in the cosmological applications.
We show how to deal with these problems and carry on a Fisher matrix analysis
to infer the accuracy on cosmological parameters achieved by this method.Comment: 8 pages, 2 figures, 2 tables, accepted for publication on Monthly
Notices of Royal Astronomical Societ
Reconciling dark energy models with f(R) theories
Higher order theories of gravity have recently attracted a lot of interest as
alternative candidates to explain the observed cosmic acceleration without the
need of introducing any scalar field. A critical ingredient is the choice of
the function f(R) of the Ricci scalar curvature entering the gravity Lagrangian
and determining the dynamics of the universe. We describe an efficient
procedure to reconstruct f(R) from the Hubble parameter depending on the
redshift z. Using the metric formulation of f(R) theories, we derive a third
order linear differential equation for f(R(z)) which can be numerically solved
after setting the boundary conditions on the basis of physical considerations.
Since H(z) can be reconstructed from the astrophysical data, the method we
present makes it possible to determine, in principle, what is the f(R) theory
which best reproduces the observed cosmological dynamics. Moreover, the method
allows to reconcile dark energy models with f(R) theories finding out what is
the expression of f(R) which leads to the same H(z) of the given quintessence
model. As interesting examples, we consider "quiessence" (dark energy with
constant equation of state) and the Chaplygin gas.Comment: 15 pages, 4 figures, accepted for publication on Physical Review
- …