Asymptotic Weak Gravity Conjecture in M-theory on K3× K3

The Asymptotic Weak Gravity Conjecture (WGC) has been proposed as a special case of the Tower WGC that probes infinite distances in the moduli space corresponding to weakly coupled gauge regimes. The conjecture has been studied in M-theory on a Calabi–Yau threefold (CY3) with finite volume inducing a 5D effective quantum field theory. In this paper, we extend the scope of the previous study to encompass lower dimensions, particularly we generalize the obtained 5D Asymptotic WGC to the effective field theory (EFT3D) coupled to 3D gravity that descends from M-theory compactified on a Calabi–Yau fourfold with an emphasis on K3× K3. We find that the CY4 has three fibration structures labeled as line Type-T², surface Type-S, and bulk Type-V. The emergent EFT3D is shown to have 2+2 towers of particle states termed as the BPS T_Mₖ→ 0^ BPS and T_Mₖ→ ∞ ^ BPS as well as the non-BPS T_Mₖ→ 0^ N-BPS and T_Mₖ→ ∞ ^ N-BPS. To ensure the viability of the 3D Asymptotic WGC, we give explicit calculations to thoroughly test the Swampland constraint for both the weakly and strongly gauge coupled regimes. Additional aspects, including the gauge symmetry breaking and duality symmetry, are also investigated.