Eccentricity Evolution of Warm Jupiters: The Role of Distant Perturbers and nearby Companions

Abstract Warm Jupiters (WJs)—giant exoplanets with orbital periods between 10 and 200 days—exhibit a broad range of eccentricities and are often accompanied by nearby low-mass planets. Understanding the origins of their orbital architectures requires examining both their migration histories and subsequent dynamical interactions. In this study, we perform extensive N -body simulations to explore how distant giant planet perturbers affect the eccentricity evolution of WJs and the role of nearby super-Earth (SE) companions in mediating these interactions. We find that while distant perturbers can induce large-amplitude eccentricity oscillations in WJs via the von Zeipel–Lidov–Kozai mechanism, the presence of nearby SE companions often suppresses these variations via strong dynamical coupling. This mechanism naturally leads to a bimodal eccentricity distribution: WJs with nearby companions tend to maintain low eccentricities, whereas those without exhibit significantly broader eccentricity distributions. We show that reproducing the observed eccentricity distribution of WJs lacking nearby companions is most naturally explained if a substantial fraction of distant perturbers occupy dynamically extreme orbits, either with large mutual inclinations or high orbital eccentricities. These results support a scenario in which WJs experience substantial postdisk dynamical evolution, shaped jointly by distant perturbers and nearby companions.