49 research outputs found
Wavelets in the Transport Theory of Heterogeneous Reacting Solutes
Рассматривается дисперсионное уравнение одномерной конвекции (адвекции) теории транспорта гетерогенных реагирующих растворенных веществ в пористых средах. Вейвлетное решение получено в рамках мультирезольвентного анализа.Розглядається дiсперсiйне рiвняння одновимiрної конвекцiї (адвекцiї) теорiї транспорту гетерогенних реагуючих розчинених речовин у пористих середовищах. Вейвлетний розв'язок одержано в рамках мультирезольвентного аналiзу.In this paper we consider the one-dimensional convection (advection) dispersion equation of the transport theory of heterogeneous reacting solutes in porous media. A wavelet solution is in the framework of multi-resolution analysis
Fast and Accurate Computation Tools for Gravitational Waveforms from Binary Sistems with any Orbital Eccentricity
The relevance of orbital eccentricity in the detection of gravitational
radiation from (steady state) binary stars is emphasized. Computationnally
effective fast and accurate)tools for constructing gravitational wave templates
from binary stars with any orbital eccentricity are introduced, including tight
estimation criteria of the pertinent truncation and approximation errors.Comment: submitted to Mon. Not. Roy. Astron. Soc., under review. 11 Pages, 45
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Sulla sesta distorsione elementare di Volterra per un cilindro cavo omogeneo e isotropo di altezza finita con carico alla Saint Venant
In this work we consider the sixth elementary Volterra's distortion for a circular hollow, homogeneous, elastic, isotropic cylinder, to analyze the load acting on the bases as a Saint Venant characteristic external stress. In this way we are able to prove that the specific load connected to the sixth distortion and examined as external stress, is equivalent (in Saint Venant's theory) to a right combined compressive and bending stress (or to a right combined tensile and bending stress)
Fantappie's group as an extension of special relativity on Cantorian space-time
In this paper we will analyze the Fantappie group and its properties in
connection with Cantorian space-time. Our attention will be focused on the
possibility of extending special relativity. The cosmological consequences of
such extension appear relevant, since thanks to the Fantappie group, the model
of the Big Bang and that of stationary state become compatible. In particular,
if we abandon the idea of the existence of only one time gauge, since we do not
see the whole Universe but only a projection, the two models become compatible.
In the end we will see the effects of the projective fractal geometry also on
the galactic and extra-galactic dynamics.Comment: 14 pages, accepted in Chaos, Solitons and Fractal
A Nonsingular Brans Wormhole: An Analogue to Naked Black Holes
In a recent paper, we showed the Jordan frame vacuum Brans Class I solution
provided a wormhole analogue to Horowitz-Ross naked black hole in the wormhole
range -3/2<{\omega}<-4/3. Thereafter, the solution has been criticized by some
authors that, because of the presence of singularity in that solution within
this range, a wormhole interpretation of it is untenable. While the criticism
is correct, we show here that (i) a singularity-free wormhole can actually be
obtained from Class I solution by performing a kind of Wick rotation on it,
resulting into what Brans listed as his independent Class II solution (ii) the
Class II solution has all the necessary properties of a regular wormhole in a
revised range -2<{\omega}<-3/2 and finally, (iii) naked black holes, as
described by Horowitz and Ross, are spacetimes where the tidal forces attain
their maxima above the black hole horizon. We show that in the non-singular
Class II spacetime this maxima is attained above the throat and thus can be
treated as a wormhole analogue. Some related issues are also addressed.Comment: 20 pages, 4 figure
Stochastic Self-Similar and Fractal Universe
The structures formation of the Universe appears as if it were a classically
self-similar random process at all astrophysical scales. An agreement is
demonstrated for the present hypotheses of segregation with a size of
astrophysical structures by using a comparison between quantum quantities and
astrophysical ones. We present the observed segregated Universe as the result
of a fundamental self-similar law, which generalizes the Compton wavelength
relation. It appears that the Universe has a memory of its quantum origin as
suggested by R.Penrose with respect to quasi-crystal. A more accurate analysis
shows that the present theory can be extended from the astrophysical to the
nuclear scale by using generalized (stochastically) self-similar random
process. This transition is connected to the relevant presence of the
electromagnetic and nuclear interactions inside the matter. In this sense, the
presented rule is correct from a subatomic scale to an astrophysical one. We
discuss the near full agreement at organic cell scale and human scale too.
Consequently the Universe, with its structures at all scales (atomic nucleus,
organic cell, human, planet, solar system, galaxy, clusters of galaxy, super
clusters of galaxy), could have a fundamental quantum reason. In conclusion, we
analyze the spatial dimensions of the objects in the Universe as well as
spacetime dimensions. The result is that it seems we live in an El Naschie's E
infinity Cantorian spacetime; so we must seriously start considering fractal
geometry as the geometry of nature, a type of arena where the laws of physics
appear at each scale in a self--similar way as advocated long ago by the
Swedish school of astrophysics.Comment: 17 pages, 3 figures, accepted by Chaos, Solitons & Fractla