In graduate studies, particularly for PhDs, students typically focus on a single research project over several years, making the concept of a double major impractical. While interdisciplinary study is possible, it usually requires collaboration with a supervisor and is not equivalent to an undergraduate double major. Graduate programs generally accept students into one specific program, although some institutions may allow students to take classes in other fields or pursue multiple concentrations, primarily in Master's programs rather than PhDs. Computational physics and science programs can be a good option for those interested in both physics and computer science. Some schools have provisions for interdisciplinary studies, provided they are not overly obscure, allowing students to work with faculty from other departments while remaining within their primary department.