Quantum Gravity corrections and entropy at the Planck time

Abstract

We investigate the effects of Quantum Gravity on the Planck era ofthe universe. In particular, using different versions of theGeneralized Uncertainty Principle and under specific conditionswe find that the main Planck quantities such as the Planck time,length, mass and energy become larger by a factor of order10−104 compared to those quantities which result from theHeisenberg Uncertainty Principle. However, we prove that thedimensionless entropy enclosed in the cosmological horizon at the Planck timeremains unchanged. These results, though preliminary, indicate that we should anticipatemodifications in the set-up of cosmology since changes in the Planck era will be inheritedeven to the late universe through the framework of Quantum Gravity (or Quantum Field Theory)which utilizes the Planck scale as a fundamental one. More importantly, these correctionswill not affect the entropic content of the universe at the Planck timewhich is a crucial element for one of the basic principles of Quantum Gravity named Holographic Principle.