Abstract: The simplest unified extension of the Minimal Supersymmetric Standard Model with bilinear R–Parity violation provides a predictive scheme for neutrino masses and mixings which can account for the observed atmospheric and solar neutrino anomalies. Despite the smallness of neutrino masses R-parity violation is observable at present and future high-energy colliders, providing an unambigu...

We establish new convergence results, in strong topologies, for solutions of the parabolic-parabolic Keller–Segel system in the plane, to the corresponding solutions of the parabolic-elliptic model, as a physical parameter goes to zero. Our main tools are suitable space-time estimates, implying the global existence of slowly decaying (in general, nonintegrable) solutions for these models, under...

We consider the large time behavior of solutions for a hyperbolic relaxation system. For a certain class of initial data the solution is shown to converge to relaxation rarefaction profiles at a determined asymptotic rate. The result is established without the smallness conditions of the wave strength and the initial disturbances. 2001 Academic Press

The problem of partial exact controllability for linear thermo-viscoelasticity is considered. Using classical multiplier techniques, a boundary observability inequality is established under smallness restrictions on coupling parameters and relaxation functions. Then, via the Hilbert Uniqueness method, the result of partial exact controllability is obtained with Dirichlet boundary controls actin...

In this article, the transport operator with general boundary conditions is discussed. According to a smallness hypothesis on the boundary operator and to finite time of sojourn property of phase spaces, we prove that the transport operator generates a strongly continuous semigroup and we give its upper bound.

We present a model with a complex and a real scalar fields and a potential whose symmetry is explicitly broken by Planck-scale physics. For exponentially small breaking, the model accounts for the period of inflation in the early universe and for the period of acceleration of the late universe or for the dark matter, depending on the smallness of the explicit breaking.

We consider the large time behavior of solutions for a hyperbolic relaxation system. For a certain class of initial data the solution is shown to converge to relaxation rarefaction prooles at a determined asymptotic rate. The result is established without the smallness conditions of the wave strength and the initial disturbances.

A modulated Fourier expansion in time is used to show long-time nearconservation of the harmonic actions associated with spatial Fourier modes along the solutions of nonlinear wave equations with small initial data. The result implies the long-time near-preservation of the Sobolev-type norm that specifies the smallness condition on the initial data.

The characteristic scale of neutral current, provided by an extension of Standard Model with a local group over the right-handed fermions, determines the smallness of neutrino masses of Dirac kind. The experimental observation of neutrino oscillations imposes the stringent limit on the Z ′ physics appearance at low energies.

A global-in-time existence theorem for classical solutions of the Vlasow-Darwin system is given under the assumption of smallness of the initial data. Furthermore it is shown that in case of spherical symmetry the system degenerates to the relativistic Vlasov-Poisson system.