Asymptotic Hodge Theory in String Compactifications and Integrable Systems

Abstract: In this thesis we study the framework of asymptotic Hodge theory and its applications in both the string landscape and the landscape of 2d integrable field theories. We show how this mathematical framework allows for a general characterization of the asymptotic behaviour of physical couplings in low-energy effective theories coming from string theory, and apply this knowledge to investigate the finiteness and geometric structure of the string landscape landscape. At the same time, we find that the defining equations of variations of Hodge structure also arise in the context of certain integrable field theories, which opens the way to finding new classes of very general solutions to said models. Part I reviews the relevant aspects of type IIB / F-theory flux compactifications and the resulting landscape of 4d low-energy effective $\mathcal{N}=1$ supergravity theories. Part II provides an in-depth discussion on asymptotic Hodge theory, including detailed explanations on the nilpotent orbit theorem of Schmid, and the multi-variable Sl(2)-orbit theorem of Cattani, Kaplan, and Schmid. This part of the thesis also contains new results regarding the multi-variable bulk reconstruction procedure, which have not appeared in the author's previous publications. Part III concerns the application of the aforementioned results to study the finiteness of the F-theory flux landscape. Additionally, motivated by recent advances in the field of o-minimal geometry and the theory of unlikely intersections, we propose three conjectures which aim to address finer features of the flux landscape. Part IV investigates two corners of the landscape of 2d integrable non-linear sigma-models, namely the $\lambda$-deformed gauged WZW model and the critical bi-Yang-Baxter model. Notably, it is shown that asymptotic Hodge theory can be used to find broad classes of solutions these models.