Thanks for posting this! For someone introduced to spinors via Clifford algebras, with the applications to physics distant, this was very helpful to read. Some

Thanks for posting this! For someone introduced to spinors via Clifford algebras, with the applications to physics distant, this was very helpful to read. Some small points - The remarks on 'double cover' in Section 5 can be improved. 'Double cover' usually doesnt refer to the dimension of the vector space which the groups acts on, but rather the geometric fact there is map from SU(2) to SO(3) which takes 2 points to a single point. For example see, https://indico.cern.ch/event/243629/attachments/415251/576988/L2.pdf https://indico.cern.ch/event/243629/attachments/415251/57698... Writing SO(4) as SU(2)+SU(2) also doesnt make sense for this reason. The simplest example of double cover being the map z → z^2 for unit circle in complex plane or in terms of angles θ → 2θ. This also relates to the 'square root' and 'half' remark in the first paragraph of Introduction. The general definiton of 'covering space' in a topology text book can be useful to read. Also, I think there is a typo in RHS of Eqn 3.1.2. But again, this was really helpful to read for someone who learnt the formal definition long time ago and was out of touch with spinors.