1,720,992 research outputs found
Fine Structure Constant, Domain Walls, and Generalized Uncertainty Principle in the Universe
Full text linkWe study the corrections to the fine structure constant from the generalized uncertainty principle in the spacetime of a domain wall. We also calculate the corrections to the standard formula to the energy of the electron in the hydrogen atom to the ground state, in the case of spacetime of a domain wall and generalized uncertainty principle. The results generalize the cases known in literature
Perturbation theory with a variational basis: The Generalized Gaussian effective potential
No full textThe perturbation theory with a variational basis is constructed and analyzed. The generalized Gaussian effective potential is introduced and evaluated up to second order for self-interacting scalar fields in one and two spatial dimensions. The problem of the renormalization of the mass is discussed in detail. Thermal corrections are incorporated. The comparison between the finite temperature generalized Gaussian effective potential and the finite temperature effective potential is critically analyzed. The phenomenon of the restoration at high temperature of the symmetry broken at zero temperature is discussed
Generalized Gaussian effective potential: Second order thermal corrections
No full textWe discuss the finite temperature generalized Gaussian effective potential. We put out a very simple relation between the thermal corrections to the generalized Gaussian effective potential and those of the effective potential. We evaluate explicitly the second-order thermal corrections in the case of the self-interacting scalar field in one spatial dimension
Generalized Gaussian effective potential: Low dimensional scalar fields
No full textWe study a generalization of the Gaussian effective potential for self-interacting scalar fields in one and two spatial dimensions. We compute the two-loop corrections and discuss the renormalization of the generalized Gaussian effective potential
Inhomogeneous and anisotropic Universe and apparent acceleration
No full textIn this paper, we introduce a Lemaître-Tolman-Bondi (LTB) Bianchi type I (plane symmetric) model of the Universe. We study and solve Einstein field equations. We investigate the effects of such a model of the Universe; in particular, these results are important in understanding the effect of the combined presence of an inhomogeneous and anisotropic universe. The observational magnitude-redshift data deviated from the UNION 2 catalog have been analyzed in the framework of this LTB anisotropic universe, and the fit has been achieved without the inclusion of any dark energy
Dynamical symmetry breaking in planar QED
No full textWe investigate (2 + 1)-dimensional QED coupled with Dirac fermions both at zero and finite temperature. We discuss in derail two-component (P-odd) and four-component (P-even) fermion fields. We focus on P-odd and P-even Dirac fermions in the presence of an external constant magnetic field. In the one-loop approximation we find that the spontaneous generation of a uniform magnetic condensate is energetically favoured in the case of the P-odd massive theory. Moreover, we find that the spontaneous generation of the magnetic condensate survives even at infinite temperature, We also discuss the spontaneous generation of fermion mass in the presence of an external magnetic field
Finite-temperature generalized Gaussian effective potential
No full textWe evaluate the thermal corrections to the generalized Gaussian effective potential. We carry out the calculations df the lowest-order corrections in the case of self-interacting scalar fields in one and two spatial dimensions, and study the restoration of the symmetry at high temperatures
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