Kleshchev, AlexanderBuursma, Doeke2020-09-242020-09-242020-09-24https://hdl.handle.net/1794/25676We give an explicit description of the category of Yoneda extensions of standard modules over KLR algebras for two special cases in Lie type A. In these two special cases, the A-infinity category structure of the Yoneda category is formal. We give an example to show that, in general, the A-infinity category structure of the Yoneda category is non-formal.en-USAll Rights Reserved.A-infinity AlgebrasCategorificationHomological AlgebraKhovanov-Lauda-Rouquier AlgebrasRepresentation TheoryElectronic Thesis or Dissertation