Operator ordering ambiguity and third quantization

Abstract In this paper, we will constrain the operator ordering ambiguity of Wheeler-DeWitt equation by analyzing the quantum fluctuations in the universe. This will be done using a third quantized formalism. It is expected that the early stages of the universe are dominated by quantum fluctuations. Furthermore, it is also expected that these quantum fluctuations get suppressed with the expansion of the universe. We will show that this desired behavior of quantum fluctuations could be realized by wide ranges of the factor ordering parameter. We will examine two different cosmological models, and observe that similar ranges of factor ordering parameter produce this desired behavior in both those cosmological models.