Gravitation ciufolini i vittorio n gorini v coccia e peron r
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For high energies we recover the classical half-period limit. A possible theoretical basis for the Chaplygin gas in cosmology is discussed. We discuss ex- plicit applications to Minkowski, de Sitter and anti-de Sitter quantum eld theories. The typical scale ofthese fluctuations is much larger than the horizon. Then it focuses on approximation methods, mainly the post-Newtonian formalism and the relaxed Einstein equations, with a discussion on how they are used in treating experimental tests and in the problem of generation and detection of gravitational waves. We give an explicit expression of the stationary state in the case of two classical oscillators.

We show that such processes may be equivalently obtained as classical limits of quantum dynamical semigroups derived in the weak coupling limit. It matches the published version Ultrashort laser pulse filaments in dispersive nonlinear Kerr media induce a moving refractive index perturbation which modifies the space-time geometry as seen by co-propagating light rays. The introduction sets the scene and provides a context for the remaining chapters. Geometry and Physics of Branes provides an introduction to current research in some of these different areas, both in physics and mathematics. The relevant parametrizations that we consider are the strengths of the polarities of the interaction, the relaxation rates of the different multipoles and the transition probabilities per unit time among the Zeeman sublevels. This decomposition presents a remarkable analogy with the holography principle, in the sense that physics in d + 1 dimensions may be encoded into the physics in one dimension less. .

We discuss a general form of quantum detailed balance and its relation to thermal relaxation and to microreversibility. La formazione di ognuno di loro costa allo Stato italiano centinaia di migliaia di euro. While particle physics offers insight to early universe physics, there is a need to understand gravity at extremes of large and short distances to further understand cosmology and the development of the universe. Gravitation: From the Hubble Length to the Planck Length fulfills this need by providing an overview of relativistic astrophysics, early universe physics, cosmology, and their interface with particle physics. Gravitation: From the Hubble Length to the Planck Length fulfills this need by providing an overview of relativistic astrophysics, early universe physics, cosmology, and their interface with particle physics. Technological developments have led us to the brink of their direct observation, which could become a reality in the coming years. Applying such expansions to the survival amplitude of a decaying state, one finds that resonances give discrete contributions with purely exponential time behavior; the background is of course present, but explicitly separated.

The formalism is applied to the Lee-Friedrichs model and to the scattering of a spinless particle by a local central potential. As pure mathematical constructions, they are tools for exploiting the fundamental laws of physics. As astronomical sources, they are part of our cosmic landscape, warping space-time, coupled to the large-scale properties and life cycle of their host. Finally, the equation to be satisfied by an event horizon is also displayed and briefly discussed. Moreover in a context a la Randall{Sundrum, the method outlined here allows a mechanism of generation of mass-spectra in the 3-brane or more generally a d 1-brane.

The poles of the eigenvector families give origin to other eigenvectors of the Hamiltonian: the singularities of the ''out'' eigenvector family are the same as those of the continued S matrix, so that resonances are seen as eigenvectors of the Hamiltonian with eigenvalue equal to their location in the complex energy plane. In the early 1980s, many physicists looked to eleven-dimensional supergravity in the hope that it might provide that elusive superunified theory. The conditions created in particle accelerators are similar to those at the time of the early universe. Cosmology is a relatively new science, but cosmological questions are as old as mankind. Pur se ricco di talenti, il Bel Paese si dimostra carente dal punto di vista degli investimenti, anche per il limitato sostegno del settore privato a un già incerto e inadeguato sostegno pubblico. The latter arises from generalized eigenvectors associated to complex eigenvalues on background contours in the complex plane, and gives the corrections to the exponential law.

Comment: 6 pages, 2 figures Branes are solitonic configurations of a string theory that are represented by extended objects in a higher-dimensional space-time. We provide a method to decompose the two-point function of a quantum field on a warped manifold in terms of fields living on a lower-dimensional manifold. As an application, a lemma due to O'Raifeartaigh is generalized to a wide class of inhomogeneous structures. There is no more equator and all solutions have the geometry of a truncated spheroid with the same type of singularity. The heat equation is obtained in the hydrodynamic limit, and it is proved that it completely describes the macroscopic behavior of the model. By analyzing the asymptotic behavior for large energies of the eigenfunctions of the continuous spectrum we also show that, as expected, tau E approaches the classical value for large values of E, thus diverging for the step-linear case and vanishing for the step-exponential one.

The relevance of these higher-order corrections stems from the fact that the characteristic time τ1 cannot be much smaller than for quantum surroundings at temperature T. For particular choices of the initial conditions, the universe, which does mimic for a long time a de Sitter—like expansion, ends up in a finite time in a special type of singularity that we call a big brake. The second case arises when the modulus of the pressure exceeds the energy density the phantom Chaplygin gas. These transformations, which seem to set up a favourable framework for the introduction of tachyons, are possible in the real case only for a two-dimensional space-time and have to be introducedad hoc, while in the scheme which is proposed here they arise naturally. By using the principle of relativity, together with the customary assumptions concerning the nature of the space-time manifold in special relativity, namely, space-time homogeneity and isotropy of space, a simple but rigorous proof is given of the reciprocity relation for the relative motion of two inertial frames of reference, which is usually assumed as a postulate in the standard derivations of the Lorentz transformations without the principle of invariance of light velocity. We exploit the gauge-invariant formalism to analyse the perturbative behaviour of two cosmological models based on the generalized Chaplygin gas describing both dark matter and dark energy in the present Universe. Questo volume, attraverso specifici contributi disciplinari e la parziale pubblicazione del lavoro di tesi di alcuni corsisti, vuole testimoniare le attività realizzate durante la I edizione del Master e i Corsi sulla modalità di formazione dei formatori.

Chapters cover an extensive array of topics, from refined experimental techniques in gravitational physics to cosmology and the quantum frontier. We highlight the existence of favorable conditions for the study of analogue black hole kinematics and Hawking type radiation. This leads us to study a specific one-parameter family of tachyonic models based on a perfect fluid mixed with a positive cosmological constant. Comment: 13 pages, 4 figures We review the essential features of the Chaplygin gas cosmological models and provide some examples of appearance of the Chaplygin gas equation of state in modern physics. We discuss explicit applications to Minkowski, de Sitter and anti-de Sitter quantum field theories.

This book presents an overview of the current understanding of gravitation, with a focus on the current efforts to test its theory, especially general relativity. The introduction sets the scene and provides a context for the remaining chapters. Comment: 14 pages, 7 figures Optical pulse propagation in nonlinear Kerr media finds an elegant description in terms of particular spacetime metrics. The resolvent of the Hamiltonian, restricted to the nuclear space appearing in the rigged Hilbert space, can be continued across the absolutely continuous spectrum; the singularities of the continuation are the same as those of the ''out'' eigenvectors. Nato con premesse di modernità e visioni strategiche di raccordo col mondo produttivo, ma poi sacrificato a prospettive talvolta poco lungimiranti e indebolito dalla progressiva riduzione delle risorse, esso ha regalato migliaia di giovani ad atenei e istituzioni straniere. Then we extend the formalism to the treatment of the 2n-point function of which we give a spectral representation which displays all the symmetry properties of the fundamental equation. Real Lie-algebra inhomogenizations are considered for complex defining representations and some emphasis is devoted to the case when the defining representation is irreducible.

For quantum systems with variable particle numbers, the same kind of assumptions leads to the grand-canonical ensemble. Chapters cover an extensive array of topics, from refined experimental techniques in gravitational physics to cosmology and the quantum frontier. I capitoli copriranno un esteso insieme di argomenti, da dalle raffinate tecniche sperimentali usate nella fisica gravitazionale alla cosmologia e la frontiera della quantistica. We solve the eigenvalue equation by the integral representation method, which allows us to classify the independent solutions as equivalence classes of homotopic paths in the complex plane. Gravity From the Hubble Length to the Planck Length a cura di I. Such a crossing is made possible by certain transformations of matter properties.