Reply to "Comment on Fine Structure Constant in the Spacetime of a Cosmic String"

In this Reply, using E.R. Bezerra de Mello's comment, I correct calculations and results presented in Phys. Lett. B 614 (2005) 140-142 about fine structure constant in the spacetime of a cosmic string.Comment: 4 pages, accepted for publication in Phys. Lett.

Corrections to the Fine Structure Constant in the Spacetime of a Cosmic String from the Generalized Uncertainty Principle

We calculate the corrections to the Fine Structure Constant in the spacetime of a cosmic string. These corrections stem from the generalized uncertainty principle. In the absence of a cosmic string our result here is in agreement with our previous result.Comment: 8 pages, accepted for publication in Phys.Lett.

Chaotic Inflation with Variable Space Dimensions

Assuming the space dimension is not constant but decreases during the expansion of the Universe, we study chaotic inflation with the potential $m^2 \phi^2/2$. We write down field equations in the slow-roll approximation and define slow -roll parameters by assuming the space dimension to be a dynamical parameter. The dynamical character of the space dimension shifts the initial and final value of the inflaton field to larger values, producing delayed chaotic inflation. We obtain an upper limit for the space dimension at the Planck length. This result is in agreement with previous works on the effective time variation of the Newtonian gravitational constant in a model Universe with variable space dimensions. We present some cosmological consequences and calculate observable quantities including the spectral indices, their scale-dependence, and the mass of the inflaton field.Comment: 4 pages, 2 figures, to appear in the proceedings of the CAPP2000, eds. Ruth Durrer, Juan Garcia-Bellido, and Mikhail Shaposhnikov, Verbier (Switzerland), July 17-28, 200