[en] To investigate the mass generating problem without Higgs mechanism we present a model in which a new scalar gauge coupling is naturally introduced. Because of the existence of production and annihilation for particles in quantum eld theory, we extend the number of independent variables from conventional four space-time dimensions to five ones in order to describe all degrees of freedom for field functions while the conventional space-time is still retained to be the background. The potential fifth variable is nothing but the proper time of particles. In response, a mass operator (m-circumflex = -iħ∂/∂_T) should be introduced. After that, the Lagrangian for free fermion fields in terms of five independent variables and mass operator is written down. By applying the gauge principle, three kinds of vector gauge couplings and one kind of scalar gauge coupling are naturally introduced. In the current scenario, the mass spectrum for all fundamental particles is accounted for in principle by solving the eigenvalue of mass operator under the function of all kinds of interactions. Moreover, there no any auxiliary mechanism including spontaneous symmetry breaking get involved in the model. Therefore, traditional problems in the standard model such as the vacuum energy problem are removed from our model, as well as the hierarchy problem on the mass spectrum for fundamental particles. (author)

[en] This work provides an accurate study of the spin-1/2 relativistic particle in a magnetic field in NC phase space. By detailed calculation we find that the Dirac equation of the relativistic particle in a magnetic field in noncommutative space has similar behaviour to what happens in the Landau problem in commutative space even if an exact map does not exist. By solving the Dirac equation in NC phase space, we not only obtain the energy level of the spin-1/2 relativistic particle in a magnetic field in NC phase space but also explicitly offer some additional terms related to the momentum-momentum non-commutativity. (authors)

[en] Recent fits of cosmological parameters by first-year Wilkinson Microwave Anisotropy Probe (WMAP) measurements seem to favour a primordial scalar spectrum with a large varying index from blue to red. We use the inflationary flow equations to reconstruct large running index inflaton potentials and comment on the current status of the inflationary flow. We find that previous negligence of higher order slow-rolling contributions when using the flow equations would lead to unprecise results

[en] The role of the auxiliary scalar field φ of BD theory in baryon number asymmetry is discussed in this paper. The authors consider a derivative coupling of this gravitational scalar field to the baryon current J_B^μ or the current of the baryon number minus lepton number J_b-L^μ based on a series of works of R. Morganstern about the Brans-Dicke cosmology. The authors find that the spontaneous baryogenesis by this coupling is able to yield sufficient baryon asymmetry n_B/s∼10^-10 provided the time of the grand unification is a little bit earlier. In addition, Davoudiasl et al have recently introduced a new type of interaction between the Ricci scalar R and the baryon current J^μ, δ_μRJ^μ and also proposed a mechanism for baryogenesis, the gravitational baryogenesis. However, the Einstein equation tells us that R-derivative=0 in the radiation-dominated epoch of the standard FRW cosmology. The authors reconsider the feasibility of having gravitational baryogenesis with such a form of interaction in radiation-filled BD cosmology. The authors show that R-derivative does not vanish in this case and the required baryon number asymmetry can also be achieved. (authors)