Gerardo Iovane

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 Naschies 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.

Varying G, accelerating Universe, and other relevant consequences of a stochastic self-similar and fractal Universe

In this paper the time dependence of G is presented. It is a simple consequence of the Virial Theorem and of the self-similarity and fractality of the Universe. The results suggest a Universe based on El Naschies Cantorian space-time. Moreover, we show the importance of the Golden Mean in respect to the large scale structures. Thanks to this study the mass distribution at large scales and the correlation function are explained and are natural consequences of the evaluated varying G. We demonstrate the agreement between the present hypotheses of segregation with a size of astrophysical structures, by using a comparison between quantum quantities and astrophysical ones. It appears clear that the Universe has a memory of its quantum origin. This appears in the G dependence too. Moreover, we see that a G=G(t) in El Naschies Cantorian space-time can imply an accelerated Universe.

On stress analysis for cracks in elastic materials with voids

Abstract The paper deals with classical problem for cracks dislocated in a certain very specific porous elastic material, described by a Cowin–Nunziato model. We propose a method based upon a reducing of stress concentration problem for cracks to some integral equations. By applying Fourier integral transforms the problem is reduced to some integral equations. For the plane-strain problem we operate with a direct numerical treatment of a hypersingular integral equation. In the axially symmetric case, for the penny-shaped crack, the problem is reduced to a regular Fredholm integral equation of the second kind. In the both cases we study stress-concentration factor, and investigate its behavior versus porosity of the material. More in particular the stress concentration factor in the medium with voids is always higher, under the same conditions, than in the classical elastic medium made of material of the skeleton. Further, as can be seen, the influence of the porosity becomes more significant for larger cracks; that is also quite natural from a physical point of view.

Microlensing search towards M31

We present the first results of the analysis of data collected during the 1998-99 observational campaign at the 1.3 meter McGraw-Hill Telescope, towards the Andromeda galaxy (M 31), aimed to detect gravitational microlensing effects as a probe for the presence of dark matter in our Galaxy and in the M 31 halo. The analysis is performed using the pixel lensing technique, which consists of the study of flux variations of unresolved sources and has been proposed and implemented by the AGAPE collaboration. We carry out a shape analysis by demanding that the detected flux variations be achromatic and compatible with a Paczynski light curve. We apply the Durbin-Watson hypothesis test to the residuals. Furthermore, we consider the background of variables sources. Finally five candidate microlensing events emerge from our selection. Comparing with the predictions of a Monte Carlo simulation, assuming a standard spherical model for the M 31 and Galactic haloes, and typical values for the MACHO mass, we find that our events are only marginally consistent with the distribution of observable parameters predicted by the simulation.

Fantappiè's group as an extension of special relativity on ε(∞) 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.

SPATIAL BEHAVIOR IN DYNAMICAL THERMOELASTICITY BACKWARD IN TIME FOR POROUS MEDIA

The aim of this paper is to study the spatial behavior of the solutions to the final-boundary-value problems associated with the linear theory of elastic materials with voids. More precisely, the present study is devoted to porous materials with a memory effect for the intrinsic equilibrated body forces. An appropriate time-weighted volume measure is associated with the backward-in-time thermoelastic processes. Then a first-order partial differential inequality in terms of such measure is established and it is further shown how the inequality implies the spatial exponential decay of the thermoelastic process in question.

SAINT-VENANT'S PRINCIPLE IN DYNAMIC POROUS THERMOELASTIC MEDIA WITH MEMORY FOR HEAT FLUX

In the present paper, we study a linear thermoelastic porous material with a constitutive equation for heat flux with memory. An approximated theory of thermodynamics is presented for this model and a maximum pseudofree energy is determined. We use this energy to study the spatial behavior of the thermodynamic processes in porous materials. We obtain the domain-of-influence theorem and establish the spatial decay estimates inside of the domain of influence. Furthermore, we prove a uniqueness theorem valid for finite or infinite bodies. The body is free of any kind of a priori assumptions concerning the behavior of solutions at infinity.

Fundamental solutions in antiplane elastodynamic problem for anisotropic medium under moving oscillating source

In present article we consider the problems of concentrated point force which is moving with constant velocity and oscillating with cyclic frequency in unbounded homogeneous anisotropic elastic two-dimensional medium. The properties of plane waves and their phase, slowness and ray or group velocity curves for 2D problem in moving coordinate system are described. By using the Fourier integral transform techniques and established the properties of the plane waves, the explicit representation of the elastodynamic Greens tensor is obtained for all types of source motion as a sum of the integrals over the finite interval. The dynamic components of the Greens tensor are extracted. The stationary phase method is applied to derive an asymptotic approximation of the far wave field. The simple formulae for Poynting energy flux vectors for moving and fixed observers are presented too. It is noted that in the far zones the cylindrical waves are separated under kinematics and energy. It is shown that the motion bring some differences in the far field properties. They are modification of the wave propagation zones and their number, fast and slow waves appearance under trans- and superseismic motion and so on.

Probing the nature of compact dark object at the Galactic Center by gravitational lensing

The long-standing issues of determination of the mass distribution and nature of the center of our Galaxy could be probed by a lensing experiment capable of testing the spatial and velocity distributions of stars nearby and beyond it. We propose a lensing toy-model which could be a further evidence that a massive condensation (eg a neutrino condensation) is a good candidate to explain the data ruling out the presence of a supermassive black hole.Abstract The long-standing issues of determination of the mass distribution and nature of the center of our Galaxy could be probed by a lensing experiment capable of testing the spatial and velocity distributions of stars nearby and beyond it. We propose a lensing toy-model which could be a further evidence that a massive condensation (e.g., a neutrino condensation) is a good candidate to explain the data ruling out the presence of a supermassive black hole.

NEUTRINO CONDENSATES AT CENTER OF GALAXIES AS BACKGROUND FOR THE MSW MECHANISM

The possibility is explored that neutrino condensates, possible candidates for the explanation of very massive objects in galactic centers, could act as background for the Mikheyev–Smirnov–Wolfeinstein mechanism responsible of neutrino oscillations. Assuming a simple neutrino star model with constant density, the lower limit of the mass squared difference of neutrino oscillations is inferred. Consequences on neutrino asymmetry are discussed.