Fermion soliton stars

Understand

A real scalar field coupled to a fermion via a Yukawa term can evade no-go theorems preventing solitonic solutions.

• For the first time, we study this model within General Relativity without approximations, finding static and spherically symmetric solutions that describe fermion soliton stars.
• The Yukawa coupling provides an effective mass for the fermion, which is key to the existence of self-gravitating relativistic solutions.
• We systematically study this novel family of solutions and present their mass-radius diagram and maximum compactness, which is close to (but smaller than) that of the corresponding Schwarzschild photon sphere.