Bremsstrahlung function in $\mathcal{N}=2$ SCFTs far beyond the supergravity limit

Abstract

We study the Bremsstrahlung function in two four-dimensional $\mathcal{N}=2$ superconformal gauge theories: the E-theory, with hypermultiplets in the symmetric and antisymmetric representations, and the D-theory, with antisymmetric and fundamental matter. Using matrix model techniques, we derive exact results at arbitrary coupling for the first few orders in the large-$N$ expansion. At leading order, both theories are shown to be planar equivalent to $\mathcal{N}=4$ Super Yang-Mills, while beyond the planar limit their behavior differs significantly. For the E-theory, we prove that the subleading correction is exactly given by a derivative of the free energy with respect to the coupling. This relation enables us to determine the complete strong-coupling expansion for the Bremsstrahlung function, including non-perturbative contributions, by exploiting known results for the free energy. For the D-theory, the exact expressions have a more intricate structure. We perform a detailed analysis of the strong-coupling regime of the subleading large-$N$ corrections, showing that, in this case, there are expansions in inverse powers of the coupling which truncate after finitely many terms. We further analyze the non-perturbative effects at strong coupling and derive closed-form expressions also for these contributions. These results provide precise predictions for the holographic duals of both theories beyond the supergravity approximation, probing higher orders in the large-$N$ expansion and the full subleading corrections at strong coupling.