The multipolar structure of rotating boson stars

Understand

The relativistic multipole moments provide a key ingredient to characterize the gravitational field around compact astrophysical objects.

• They play a crucial role in the description of the orbital evolution of coalescing binary systems and encode valuable information on the nature of the binary's components, which leaves a measurable imprint in their gravitational-wave emission.
• We present a new study on the multipolar structure of a class of arbitrarily spinning boson stars with quartic self-interactions in the large coupling limit, where these solutions are expected to be stable.
• Our results strengthen and extend previous numerical analyses, showing that even for the most compact configurations the multipolar structure deviates significantly from that of a Kerr black hole.