Baryon Asymmetry from the Generalized Uncertainty Principle

Abstract

We study Quantum Gravity effects in cosmology, and in particular that of the Generalized Uncertainty Principle on the Friedmann equations. We show that the Generalized Uncertainty Principle induces variations of the energy density and pressure in the radiation-dominated era which provide a viable explanation for the observed baryon asymmetry in the Universe.

Primordial Big Bang Nucleosynthesis and Generalized Uncertainty Principle

“…Therefore, one still gets the bounds ( 45)-( 46) for T ≃ (0.1 ÷ 10) MeV. 4 We point out that the gap between the bound on β from GUP baryogenesis [43] and other cosmological bounds from different stages of the evolution of the Universe could be a hint for the need of a GUP model with a time (or equivalently energy) dependent deformation parameter. Of course, such a running behavior might not be described through a simply (i.e.…”

“…For the quadratic GUP model (1), this can be done by computing the minimal change of area ∆A min = 8πℓ 2 p E ∆x of an apparent horizon absorbing a quantum particle of given energy E ≃ ∆p and finite size ∆x ≃ r s = A/π (r s = 2M G is the Schwarzschild radius). After some algebra, one gets [43,58]…”

“…The resulting expression is rather awkward to exhibit. Since we do not need it explicitly in the following analysis, we remand the interested reader to [43,58].…”

“…In a similar fashion, one can derive the linearized second GUP-modified Friedmann equation to be [43]…”

“…Let us focus on the most stringent bound (45). Except for the constraint of [43] (which is however computed by referring to the much earlier baryogenesis epoch 4 ) and that of [44] with full data Cosmology (which seems in general to display some inconsistencies between GUP and current data available on dark energy), we notice that the result β O(10 81 ) perfectly fits with other cosmological bounds obtained via Type Ia supernovae [45] and baryon acoustic oscillations measurements [45] (see Table I). It also agrees with late-time observational data from Early-Type Galaxies as Cosmic Chronometers, the H0 Lenses in COSMOGRAIL's Wellspring, the "Mayflower" sample of Gamma Ray Bursts and the latest Planck 2018 release for Cosmic Microwave Background radiation [44].…”