Graduate students in Physics are supported as either Research Assistants (RAs) or Teaching Assistants (TA). Throughout a PhD you will have financial support from these sources, covering all living expenses plus some extra. RA positions are not usually confirmed until graduate students spend some time in a research group. At OSU Dept. of Physics it is typical to spend one year as a TA while you explore research options, then secure an RA position in the second year. RA support can depend on the availability of research funding. If research funding is limited, RA positions become more competitive.