The answer to this question is entirely based on the observer. One can say the center of the universe is the center point of infinity, where all things expand from. One can also say that the center of the universe is the center of the observer. For human observers, the heart is most favored as one's center. Each individuation of the universe has its own center. As an observer, one sees the universe from that center, this creates a paradigm in which the universe has infinite centers, as the observation points are also infinite.