arXiv subjects
Publications and source records attributed to G. Papini.
Fully covariant wave equations predict the existence of a class of inertial-gravitational effects that can be tested experimentally. In these equations inertia and gravity appear as external classical fields, but, by conforming to general relativity, provide very valuable information on how Einstein's views carry through in the world of the quantum.
Spin-rotation coupling, or Mashhoon effect, is a phenomenon associated with rotating observers. We show that the effect exists and plays a fundamental role in the determination of the anomalous magnetic moment of the muon.
We consider a model in which accelerated particles experience line--elements with maximal acceleration corrections that are introduced by means of successive approximations. It is shown that approximations higher than the first need not be considered. The method is then applied to the Kerr metric. The effective field experienced by accelerated test particles contains corrections that vanish in the limit $\hbar\to 0$, but otherwise affect the behaviour of matter greatly. The corrections generate potential barriers that are external to the horizon and are impervious to classical particles.
Neutrino flavour oscillations are analyzed in a model in which particles experience an effective Schwarzschild geometry modified by maximal acceleration corrections. These imply a quantum violation of the equivalence principle. The corresponding shifts in the phase of the neutrino mass eigenstates are calculated and discussed.
Spin-1/2 particles can be used to study inertial and gravitational effects by means of interferometers, particle accelerators, and ultimately quantum systems. These studies require, in general, knowledge of the Hamiltonian and of the inertial and gravitational quantum phases. The procedure followed gives both in the low- and high-energy approximations. The latter affords a more consistent treatment of mass at high energies. The procedure is based on general relativity and on a solution of the Dirac equation that is exact to first-order in the metric deviation. Several previously known acceleration and rotation induced effects are re-derived in a comprehensive, unified way. Several new effects involve spin, electromagnetic and inertial/gravitational fields in different combinations.
We study the problem of quantization of thin shells in a Weyl-Dirac theory by deriving a Wheeler-DeWitt equation from the dynamics. Solutions are found which have interpretations in both cosmology and particle physics.
The dynamics of a relativistic particle in a Reissner-Nordstrom background is studied using Caianiello model with maximal acceleration. The behaviour of the particle, embedded in a new effective geometry, changes with respect to the classical scenario because of the formation of repulsive potential barriers near the horizon. Black hole formation by accretion of massive particles is not therefore a viable process in the model. At the same time, the naked singularity remains largely unaffected by maximal acceleration corrections.
Massive, spinless bosons have vanishing probability of reaching the sphere r=2M from the region r>2M when the original Schwarzschild metric is modified by maximal acceleration corrections.
We consider a model in which accelerated particles experience line--elements with maximal acceleration corrections. When applied to the Schwarzschild metric, the effective field experienced by accelerated test particles contains corrections that vanish in the limit $\hbar\to 0$, but otherwise affect the behaviour of matter greatly. A new effect appears in the form of a spherical shell, external to the Schwarzschild sphere, impenetrable to classical particles.
We show that, in cosmological microlensing, corrections of order $v/c \sim Δλ/λ$, to the deflection angle of light beams from a distant source are not negligible and that all microlensing quantities should be corrected up to this order independently of the cosmological model used.
Caianiello's quantum geometrical model with maximal acceleration places the upper limit $μ\leq 719.5$ GeV on the mass of the Higgs boson. The model also provides an equation linking the mass of the W boson to the Higgs mass $μ$ and independent symmetry breaking and mass generating mechanisms. These may further restrict the value of $μ$.
The maximal acceleration corrections to the Lamb shift of muonic hydrogen are calculated by using the relativistic Dirac wave functions. The correction for the $2S-2P$ transition is $\sim 0.38$ meV and is higher than the accuracy of present QED calculations and of the expected accuracy of experiments in preparation.
The dynamical process following the breaking of Weyl geometry to Riemannian geometry is considered by studying the motion of de Sitter bubbles in a Weyl vacuum. The bubbles are given in terms of an exact, spherically symmetric thin shell solution to the Einstein equations in a Weyl-Dirac theory with a time-dependent scalar field of the form beta = f(t)/r. The dynamical solutions obtained lead to a number of possible applications. An important feature of the thin shell model is the manner in which beta provides a connection between the interior and exterior geometries since information about the exterior geometry is contained in the boundary conditions for beta.
The maximal acceleration corrections to the Lamb shift of one--electron atoms are calculated in a non--relativistic approximation. They are compatible with experimental results, are in particularly good agreement with the $2S-2P$ Lamb shift in hydrogen and reduce by $\sim 50%$ the experiment--theory discrepancy for the $2S-2P$ shift in $He^+$.
Exact gauge structures arise in the evolution of spin-1/2 particles in conformally flat space-times. The corresponding Berry potentials can be Abelian or non-Abelian depending on the mass degeneracy of the system considered. Examples include de Sitter universes and maximal acceleration.
The maximal acceleration corrections to the Lamb shift of one--electron atoms are calculated starting from the Dirac equation and splitting the spinor into large and small components. The results depend on $Z^8$ and a cut-off $Λ$. Sizeable values are obtained even at Z=1 for $Λ\sim a_0/2$, where $a_0$ is the Bohr radius. These values are compatible with theoretical and experimental results.
We calculate the first order maximal acceleration corrections to the classical electrodynamics of a particle in external electromagnetic fields. These include additional dissipation terms, the presence of a critical electric field, a correction to the cyclotron frequency of an electron in a constant magnetic field and the power radiated by the particle. The electric effects are sizeble at the fields that are considered attainable with ultrashort $TW$ laser pulses on plasmas.
Following de Broglie and Vigier, a fully relativistic causal interpretation of quantum mechanics is given within the context of a geometric theory of gravitation and electromagnetism. While the geometric model shares the essential principles of the causal interpretation initiated by de Broglie and advanced by Vigier, the particle and wave components of the theory are derived from the Einstein equations rather than a nonlinear wave equation. This geometric approach leads to several new features, including a solution to the de Broglie variable mass problem.