From Fredholm Determinants to AdS/CFT Observables: A Universal Strong-Coupling Framework

We investigate the trans-series structure of the cusp anomalous dimension of $\mathcal{N}=4$ supersymmetric Yang-Mills theory and the dynamically generated mass gap of the $\mathrm{O}(6)$ sigma model at strong 't Hooft coupling. We consider the one-parameter deformation of the cusp anomalous dimension, known as the tilted cusp, and review its strong-coupling expansion obtained through its representation in terms of Fredholm determinants with a matrix Bessel kernel. The advantage of this deformation is that the non-perturbative scales separate naturally, revealing structures that remain hidden in the physical limit. Motivated by this observation, we introduce the tilted mass gap, which reduces to the physical $\mathrm{O}(6)$ mass gap at a special value of the deformation parameter and exhibits a deep connection with the tilted cusp. This formulation allows us to determine the complete strong-coupling trans-series and resurgence structure of the $\mathrm{O}(6)$ mass gap, while extending and proving conjectured relations between successive non-perturbative corrections. Building on the underlying Fredholm determinant representation, we construct an Alien calculus that generates all non-perturbative sectors of these AdS/CFT observables directly from their perturbative expansions. Finally, we derive an exact all-orders relation between the strong-coupling trans-series of the $\mathrm{O}(6)$ mass gap and the cusp anomalous dimension of planar $\mathcal{N}=4$ supersymmetric Yang-Mills theory.