Aneides hardii

Number of pages=23Geological SciencesIntegrative Biolog

Generalized Uncertainty Principle from Quantum Geometry

The generalized uncertainty principle of string theory is derived in the framework of Quantum Geometry by taking into account the existence of an upper limit on the acceleration of massive particles.Comment: 9 pages, LATEX file, to appear in Int. Jou. Theor. Phy

Maximal Acceleration Limits on the Mass of the Higgs Boson

Caianiello's quantum geometrical model with maximal acceleration places the upper limit $\mu\leq 719.5$ 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 $\mu$ and independent symmetry breaking and mass generating mechanisms. These may further restrict the value of $\mu$.Comment: LaTex file, 13 pages, to be published in Il Nuovo Cimento

Microlensing Parallax for Observers in Heliocentric Motion

Motivated by the ongoing Spitzer observational campaign, and the forecoming K2 one, we revisit, working in an heliocentric reference frame, the geometrical foundation for the analysis of the microlensing parallax, as measured with the simultaneous observation of the same microlensing event from two observers with relative distance of order AU. For the case of observers at rest we discuss the well known fourfold microlensing parallax degeneracy and determine an equation for the degenerate directions of the lens trajectory. For the case of observers in motion, we write down an extension of the Gould (1994) relationship between the microlensing parallax and the observable quantities and, at the same time, we highlight the functional dependence of these same quantities from the timescale of the underlying microlensing event. Furthermore, through a series of examples, we show the importance of taking into account the motion of the observers to correctly recover the parameters of the underlying microlensing event. In particular we discuss the cases of the amplitude of the microlensing parallax and that of the difference of the timescales between the observed microlensing events, key to understand the breaking of the microlensing parallax degeneracy. Finally, we consider the case of the simultaneous observation of the same microlensing event from ground and two satellites, a case relevant for the expected joint K2 and Spitzer observational programs in 2016.Comment: Accepted for publication in Ap

Neutrino optics and oscillations in gravitational fields

We study the propagation of neutrinos in gravitational fields using wave functions that are exact to first order in the metric deviation. For illustrative purposes, the geometrical background is represented by the Lense-Thirring metric. We derive explicit expressions for neutrino deflection, helicity transitions, flavor oscillations and oscillation Hamiltonian.Comment: 16 page

Baryogenesis in f(R)f(R)-Theories of Gravity

$f(R)$-theories of gravity are reviewed in the context of the so called gravitational baryogenesis. The latter is a mechanism for generating the baryon asymmetry in the Universe, and relies on the coupling between the Ricci scalar curvature $R$ and the baryon current. Gravity Lagrangians of the form ${\cal L}(R)\sim R^n$, where $n$ differs from 1 (the case of the General Relativity) only for tiny deviations of a few percent, are consistent with the current bounds on the observed baryon asymmetry