Algebra is one of the major branches of mathematics. If you want to get an undergraduate degree in mathematics at Harvard, you are required to take at least one course in analysis, at least one course in algebra, and at least one course in topology. I want to remark that algebra, a branch of mathematics, is not arithmetic, but a much more generalized version of arithmetic. Sometimes, it is called “abstract algebra” to distinguish itself from arithmetic, which many people also call algebra. “Linear algebra” which is the most basic subfield of algebra is very important in physics, but other than that, the importance of algebra in physics at undergraduate level is rather limited despite its importance in certain subfields of physics. Therefore, it is very easy to find physics professors who don’t know what is “Abelian group” which you will easily learn in the first article. Even though algebra is mostly learned by sophomore undergraduate math majors, anyone who has some mathematical sense can get the basic idea. It is not the ability to solve complicated equations or factoring out polynomials quickly but ability to think deeply that counts.