Twisted and exceptional Tinkertoys for Gaiotto duality

textA large class of 4d N = 2 superconformal field theories arise as compactifications of a 6d (2, 0) theory of type j = A, D, E on a punctured Riemann surface, C. These theories can be classified by listing the allowed fixtures and cylinders which can occur in a pants decomposition of C, and giving the rules for gluing them together. Different pants decompositions of the same surface give different weakly-coupled presentations of the same underlying SCFT, related by S-duality. An even larger class of theories can be constructed in this way by including "twisted" punctures, which carry a non-trivial action of the outer-automorphism group of j. In this dissertation, we discuss the classification procedure for twisted theories of type D [subscript N] , as well as for twisted and untwisted theories of type E₆. Using these results, we write the Seiberg-Witten solutions for all Spin(n) gauge theories with matter in spinor representations which can be realized by compactifying the (2, 0) theory. We also study a family of SCFTs arising from the twisted A [subscript 2N] series, whose twisted punctures are still not fully-understood.Physic