https://doi.org/10.1140/epjc/s10052-026-15332-9
Regular Article - Theoretical Physics
Chains of rotating boson stars with quartic or sextic self-interaction
1
Institute of Theoretical Physics, Lanzhou University, 730000, Lanzhou, China
2
School of Information Science and Engineering, Lanzhou University, 730000, Lanzhou, China
a
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Received:
17
December
2025
Accepted:
14
January
2026
Published online:
14
February
2026
Abstract
This paper investigates chains of rotating boson stars (BSs) within Einstein gravity coupled to a complex scalar field. The model incorporates quartic or sextic self-interactions in the scalar Lagrangian, which support the existence of stationary, solitonic, gravitationally bound solutions. We numerically construct these multi-component systems and investigate how the self-interactions alter their global properties−specifically the Arnowitt-Deser-Misner (ADM) mass M, the angular momentum J and the morphology of their ergospheres. A central result is the distinct dependence of the 
and 
relations on the parity of the chains. Specifically, systems with an even number of constituents display spiraling curves, while those with an odd number exhibit loop structures. Moreover, we observe that two initially distinct ergospheres merge into a single one as the frequency 
increases. Our analysis also indicates that the quartic interaction imposes more restrictive existence bounds, particularly for odd-numbered chains, thereby restricting stable configurations to the weak-coupling regime. In contrast, the sextic interaction has a weaker effect and enables stable solutions at substantially stronger couplings.
© The Author(s) 2026
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