Abstract

The cosmological constant problem arises because the magnitude of vacuum energy density predicted by quantum eld theory is about 120 orders of magnitude larger than the value implied by cosmological observations of accelerating cosmic expansion. We pointed out that the fractal nature of the quantum space-time with negative Hausdor- Colombeau dimensions can resolve this tension. The canonical Quantum Field Theory is widely believed to break down at some fundamental high-energy cuto  and therefore the quantum uctuations in the vacuum can be treated classically seriously only up to this high-energy cuto. In this paper we argue that Quantum Field Theory in fractal space-time with negative Hausdor-Colombeau dimensions gives high-energy cuto on natural way. We argue that there exists hidden physical mechanism which cancel divergences in canonical QED4;QCD4; Higher-Derivative - Quantum-Gravity, etc. In fact we argue that corresponding supermassive Pauli-Villars ghost elds really exists. It means that there exists the ghost-driven acceleration of the univers hidden in cosmological constant. In order to obtain desired physical result we apply the canonical Pauli-Villars regularization up to : This would t in the observed value of the dark energy needed to explain the accelerated expansion of the universe if we choose highly symmetric masses distribution between standard matter and ghost matter below that scale ;i.e., fs:m ()