Compactified 2HDM under the Non-SUSY AdS instability conjecture
arXiv:2512.16389
Abstract
We investigate how extra-dimensional dynamics influence Higgs-sector phenomenology by compactifying a Two-Higgs-Doublet Model (2HDM) coupled to 4D gravity on a circle \(S^1\). The resulting effective potential includes tree-level 2HDM interactions, one-loop Coleman--Weinberg corrections from the Kaluza--Klein towers, and an effective radion stabilization contribution inspired by the broader modulus-stabilization literature. We derive the corresponding 3D effective action and show that, for the observed Higgs mass \(m_h=125\,\mathrm{GeV}\), the compactified potential admits a stabilized configuration with near-zero vacuum energy. By imposing the non-supersymmetric AdS instability conjecture as a quantum-gravity consistency requirement, we obtain a constraint within our numerical setup on the heavy Higgs sector, finding that the additional scalar states must satisfy approximately \(M_H \gtrsim 680\,\mathrm{GeV}\) in order to avoid perturbatively stable non-supersymmetric AdS\(_3\) minima. Our results demonstrate how Swampland-inspired constraints can yield phenomenologically relevant predictions for extended Higgs sectors.
24 pages, 4 figures