I want to know the answer to the following question:
What theory did Hermann Weyl study in addition to locally compact groups?
All the background I'm provided with is that "Walther von Dyck (1882) introduced the idea of specifying a group by means of generators and relations, and was also the first to give an axiomatic definition of an "abstract group", in the terminology of the time.". Is that enough to answer the question?
Answer: no