Applying for graduate studies in a different specialization than one's undergraduate degree is possible, particularly in EU countries like the UK, but it depends heavily on the specific program and the skills acquired during undergraduate studies. Mathematics poses unique challenges, especially in pure mathematics, where foundational knowledge is crucial. Some interdisciplinary fields, such as mathematical biology, may allow for a smoother transition due to overlapping skills, like programming, that a physics background provides. Prospective students are encouraged to research individual university programs and their entry requirements, as flexibility varies significantly across institutions and countries. In some regions, particularly in German-speaking countries, strict prerequisites are enforced, requiring a relevant bachelor's degree before pursuing a master's or Ph.D. Overall, while transitioning to a different field is feasible, it often requires additional preparatory work to meet specific academic standards.