The rol of noise in the early universe

EZEQUIEL LOZANO; FRANCISCO D. MAZZITELLI

INTERNATIONAL JOURNAL OF MODERN PHYSICS D

WORLD SCIENTIFIC PUBL CO PTE LTD

Lugar: London, UK; Año: 2021

0218-2718

In this paper, we consider a quantum mechanical system to model the effect of quantumfields on the evolution of the early universe. The system consists of an inverted oscillatorbilinearly coupled to a set of harmonic oscillators. We point out that the role of noisemay be crucial in the dynamics of the oscillator, which is analyzed using the theoryof harmonic oscillators with random frequency. Using this analogy, we argue that dueto the fluctuations around its mean value, a positive vacuum energy density would notproduce an exponentially expanding but an oscillating universe, in the same fashionthat an inverted pendulum is stabilized by random oscillations of the suspension point(stochastic Kapitza pendulum). The results emphasize the relevance of noise in theevolution of the scale factor.