A contribution to the recently established Finite Action program. Path integral approach to Quantum Field Theory is one of the most popular and powerful theoretical tools used in particle physics and quantum gravity. The probability of propagation from one spacetime point to another is given by a functional integral, where one needs to sum over all possible trajectories of a particle. The integral is weighted by an exponential factor, with the classical action in the exponent. If for a given field configuration the action happens to be infinite, the corresponding probability amplitude vanishes.

The inflationary paradigm states that in the history of our universe, there was a time of exponential growth of its volume. The inflation is powered by a remarkable fuel- dark energy. The nature of dark energy is still largely unknown. The cosmological inflation, however, is in agreement with our astronomical observations. Originally, it had solved many issues with the OG cosmology. With great power, comes great responsibility- if the theory of inflation is true, we are probably living in a Multiverse. And by Multiverse, I mean a 13.8 billion-light-years wide bubble of spacetime causally disconnected with the other such "pocket universes". In this work, we provide a technical introduction to the multiverse and investigate its consequences in the context of asymptotically safe inflation.