# Alternative effective mass functions in the Mukhanov-Sasaki equation of loop quantum cosmology (Prof. Bao-Fei Li, Zhejiang University)

The linear perturbation theory is an important aspect of the research in loop quantum cosmology. It is directly related with the test of the theory by comparing the theoretical predictions with the currently available observational data. Currently, there are two popular approaches, namely the dressed metric and the hybrid approach, which investigate the possible imprints of the quantum gravity effects in the early universe. At the phenomenological level, they differ by the distinct effective mass functions in the Mukhanov-Sasaki (MS) equation of the linear perturbations. In this talk, I will talk about obtaining these mass functions at the level of effective dynamics and presenting alternative polymerization of the classical mass function that can lead to new effective mass functions as compared with those encountered in the aforementioned two approaches.