4 papers
Topological Crystals
John C. Baez
Sunada's work on crystallography emphasizes the role of the "maximal abelian cover" of a graph . This is a covering space of for which the group of deck transformations is t…
Getting to the Bottom of Noether's Theorem
John C. Baez
We examine the assumptions behind Noether's theorem connecting symmetries and conservation laws. To compare classical and quantum versions of this theorem, we take an algebraic app…
Higher Gauge Theory
Leron Borsten, Mehran Jalali Farahani, Branislav Jurco +5
This is an invited survey article on higher gauge theory for the Encyclopedia of Mathematical Physics, 2nd edition. In particular, we provide a lightning introduction to higher str…
Hoà ng Xuân SÃnh's Thesis: Categorifying Group Theory
John C. Baez
During what Vietnamese call the American War, Alexander Grothendieck spent three weeks teaching mathematics in and near Hanoi. Hoà ng Xuân SÃnh took notes on his lectures and lat…