Gravity can go from an attractive force to being a repelling force when the energy density is high enough.

Sources:

• [[multiverse - one universe or many]]
• Gasperini, M. 1998. ‘Repulsive Gravity in the Very Early Universe’. General Relativity and Gravitation 30 (12): 1703–9. https://doi.org/10.1023/A:1026606925857.