Symmetry and group theory book I would like to start learning about symmetries in physics and how they affect physical quantities. As far as I know, the mathematical language that describes symmetries is the Group Theory. So, I think the best start would be getting deep in this theory. Although there are many books on that topic, I would like to find one that would be written in a very simple way, for beginners, with many examples, preferably in the physical context. Could anyone suggest such a book?
Note: I would like to study graphene and other 2D materials such as transition metal dichalcogenides.
 A: opinion based question, so it may be closed.
The author Vincent (family name) has a very good introduction to group theory for molecules.
I like this book as it has questions for you to answer as you go along so you really learn it as you read.
If you are interested in solid state then you will have to go further to space groups with another text - this text deals with point groups.
A: Chapter 23 of Sadri Hassani's Mathematical Physics provides a solid, for a physicist, introduction to group thoery in general. This includes representation theory also. Having a bit of mathematical understanding of concepts actually helps, to understand the jargon and grasp the true meaning of equations, in my opinion.
Then read parts of Dresselhaus's book as and when needed. Also focus on the exact topic you want to know, group theory and its representations are a huge topic; even if you only want to parts relevant for a condensed matter physicist.
Oh, noticed that it is quite old question. Still, may be relevant, I hope.
