The physical nature of the cosmological constant and the decoherence scale in a renormalization-group approach

In this paper, we consider the nature of the cosmological constant as due by quantum fluctuations. Quantum fluctuations are generated at Planckian scales by noncommutative effects and watered down at larger scales up to a decoherence scale LD, where classicality is reached. In particular, we formally depict the presence of the scale at LD by adopting a renormalization group approach. As a result, an analogy arises between the expression for the observed cosmological constant. generated by quantum fluctuations and the one expected by a renormalization group approach, provided that the renormalization scale mu is suitably chosen. In this framework, the decoherence scale LD is naturally identified with the value mu(D) with mu(D) representing the minimum allowed particle-momentum for our visible universe. Finally, by mimicking renormalization group approach, we present a technique to formally obtain a nontrivial infrared (IR) fixed point at mu = mu(D) in our model.