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

Abstract

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 $L_D$ where classicality is reached. In particular, we formally depict the presence of the scale at $L_D$ by adopting a renormalization group approach. As a result, an analogy arises between the expression for the observed cosmological constant $\overline{\Lambda}$ 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 $L_D$ is naturally identified with the value ${\mu}_D$, with $\hbar{\mu}_D$ representing the minimum allowed particle-momentum for our visible universe. Finally, by mimicking renormalization group approach, we present a technique to formally obtain a non-trivial infrared (IR) fixed point at $\mu=\mu_D$ in our model.