Metaphysical Cosmology is the study or speculation about all that exists/might exist, it can include speculation about what type of God might exist. In metaphysics, it often involves questions of how a god operates and how a god might have created the universe. Religious cosmology isn't a branch of Science despite the impressive word. It tries to explain existence based on the Mythology of one or more Religions. The different mythologies contradict each other and they can't all be true.