The subject of this thesis is the rigorous construction of QFT models with nontrivial interaction. Two different approaches in the framework of AQFT are discussed. On the one hand, an inverse scattering problem is considered. A given factorizing S-matrix is thereby taken as the starting point of the construction. The particle spectrum taken into account involves an arbitrary number of massive particle species, transforming under a global gauge group. Starting from known wedge-local auxiliary fields, the transition to local theories is shown. To his end, we make use of the modular nuclearity condition and investigate certain maps from the wedge algebras, generated by the auxiliary fields, to the considered Hilbert space. Under a very plausible conjecture it is shown that these maps are nuclear, which implies the nontriviality of algebras associated with bounded regions in the sense that the Reeh-Schlieder property holds. A large class of integrable models with factorizing S-matrices in 1+1 dimensions can be constructed in this way. Among them are the O(N)-invariant nonlinear sigma-models. Deformation techniques, on the other hand, constitute a method of construction which may be applied in arbitrary spacetime dimensions. This approach starts from a known quantum field theoretic model which is subjected to a certain modification. Here, concretely, the model of a scalar massive Fermion was deformed. The emerging models are based on wedge-local fields, allowing for the computation of the two-particle S-matrix. The resulting scattering matrix depends on the deformation and differs from the one of the initial model. By restricting to 1+1 dimensions, the deformation method yields a large class of integrable models with factorizing S-matrices, including the Sinh-Gordon model.
Circular quiver gauge theories, isomonodromic deformations and $W_N$ fermions on the torus
International School of Advanced Studies (SISSA)（高等研究学院）；Institute for Geometry and Physics (IGAP)（几何与物理研究所）；INFN, Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）；Center for Advanced Studies, Skolkovo Institute of Science and Technology（斯科尔科沃科学技术学院高级研究中心）；NRU HSE, International Laboratory of Representation Theory and Mathematical Physics（国立高等经济大学表示论与数学物理国际实验室）；Bogolyubov Institute for Theoretical Physics（博戈留博夫理论物理研究所）
