Under the authority of is a phrase that specifies the control or power that an entity has over something or someone else. However, using the same phrase repeatedly can make the writing sound monotonous. To avoid this, one can use synonyms to convey the same meaning. Some of the synonyms that can be used for under the authority of include being subject to, governed by, regulated by, managed by, controlled by, in the hands of, under the jurisdiction of, under the power of, and many more. Using synonyms not only brings variety to the text but also makes it more engaging and easy to understand for readers.