arXiv subjects

G. Scarpetta

Publications and source records attributed to G. Scarpetta.

100 records · Page 6Linked to original sources

arXiv1998

Regularizing Property of the Maximal Acceleration Principle in Quantum Field Theory

It is shown that the introduction of an upper limit to the proper acceleration of a particle can smooth the problem of ultraviolet divergencies in local quantum field theory. For this aim, the classical model of a relativistic particle with maximal proper acceleration is quantized canonically by making use of the generalized Hamiltonian formalism developed by Dirac. The equations for the wave function are treated as the dynamical equations for the corresponding quantum field. Using the Green's function connected to these wave equations as propagators in the Feynman integrals leads to an essential improvement of their convergence properties.

hep-th↗

arXiv1998

Maximal Acceleration Limits on the Mass of the Higgs Boson

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 $μ$.

hep-ph↗

arXiv1998

Maximal Acceleration Corrections to the Lamb Shift of Muonic Hydrogen

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.

hep-ph↗

arXiv1998

Scalar perturbations in deflationary cosmological models

We consider scalar perturbations of energy--density for a class of cosmological models where an early phase of accelerated expansion evolves, without any fine--tuning for graceful exit, towards the standard Friedman eras of observed universe. The geometric procedure which generates such models agrees with results for string cosmology since it works if dynamics is dominated by a primordial fluid of extended massive objects. The main result is that characteristic scales of cosmological interest, connected with the extension of such early objects, are selected.}

gr-qc↗

arXiv1998

Cosmological perturbations in singularity-free, deflationary models

We consider scalar perturbations of energy-density for a class of cosmological models where an early phase of accelerated expansion evolves, without any fine-tuning for graceful exit, towards the standard Friedman eras of observed universe. The quantum geometric procedure which generates such models agrees with results for string cosmology since it works if dynamics is dominated by a primordial fluid of extended massive objects. The main result is that characteristic scales of cosmological interest, connected with the extension of such early objects, are selected.

gr-qc↗

arXiv1998

Maximal Acceleration Corrections to the Lamb Shift of Hydrogen, Deuterium and He$^{+}$

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 $He^+$.

hep-ph↗

arXiv1997

Maximal Acceleration Corrections to the Lamb Shift of One-Electron Atoms

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.

hep-th↗

arXiv1997

Classical Electrodynamics of a Particle with Maximal Acceleration Corrections

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.

hep-th↗

arXiv1995

Complete Integrability for Lagrangian Dependent on Acceleration in a Space-Time of Constant Curvature

The equations of motion for a Lagrangian ${\cal L}(k_1)$, depending on the curvature $k_1$ of the particle worldline, embedded in a space--time of constant curvature, are considered and reformulated in terms of the principal curvatures. It is shown that for arbitrary Lagrangian function ${\cal L}(k_1)$ the general solution of the motion equations can be obtained by integrals. By analogy with the flat space--time case, the constants of integration are interpreted as the particle mass and its spin. As examples, we completely investigate Lagrangians linear and quadratic in $(k_1)$ and the model of relativistic particle with maximal proper acceleration, in a space--time with constant curvature.

hep-th↗

arXiv1994

Dynamics of relativistic particle with Lagrangian dependent on acceleration

Models of relativistic particle with Lagrangian ${\cal L}(k_1)$, depending on the curvature of the worldline $k_1$, are considered. By making use of the Frenet basis, the equations of motion are reformulated in terms of the principal curvatures of the worldline. It is shown that for arbitrary Lagrangian function ${\cal L}(k_1)$ these equations are completely integrable, i.e., the principal curvatures are defined by integrals. The constants of integration are the particle mass and its spin. The developed method is applied to the study of a model of relativistic particle with maximal proper acceleration, whose Lagrangian is uniquely determined by a modified form of the invariant relativistic interval. This model gives us an example of a consistent relativistic dynamics obeying the principle of a superiorly limited value of the acceleration, advanced recently.

hep-th↗