A Comparative study of string theory and loop quantum gravity in cosmological context

Abstract

As per this study a possible comparison between String Theory and Loop Quantum Gravity is conceivable only at perturbative level in the large volume(in Planck units) limit. The simplest context of homogeneous isotropic cosmology models concentrate only on the perturbative modifications of the gravity sector alone. It is done only in the spirit of comparison between the two theories and not with an effort to relate to observations, because homogeneity and isotropy are them selves approximations to the real world. The second order term coming from string theory and Gamma square from LQC are compared. The two theories in terms of effective classical equations of motion of the underlying theory are compared. Though the equations appear to be very different, the solutions to both sets of equations predict that at least to the first order in perturbation theory the Minkowski geometry is stable.