*Article* **Gravitating Bubbles of Gluon Plasma above Deconfinement Temperature**

**Yves Brihaye 1 and Fabien Buisseret 2,3,***∗*


Received: 2 September 2020; Accepted: 8 October 2020; Published: 13 October 2020

**Abstract:** The equation of state of SU(3) Yang–Mills theory can be modelled by an effective *Z*3−symmetric potential depending on the temperature and on a complex scalar field *φ*. Allowing *φ* to be dynamical opens the way to the study of spatially localized classical configurations of the scalar field. We first show that spherically symmetric static Q-balls exist in the range (1 − 1.21) × *Tc*, *Tc* being the deconfinement temperature. Then we argue that Q-holes solutions, if any, are unphysical within our framework. Finally, we couple our matter Lagrangian to Einstein gravity and show that spherically symmetric static boson stars exist in the same range of temperature. The Q-ball and boson-star solutions we find can be interpreted as "bubbles" of deconfined gluonic matter; their mean radius is always smaller than 10 fm.

**Keywords:** deconfinement; Matter-gravity coupling; Yang–Mills theory; Q-ball; boson star
