Moduli stars

Sven Krippendorf, Francesco Muia, Fernando Quevedo

Research output: Contribution to journalArticlepeer-review


We explore the possibility that (Bose-Einstein) condensation of scalar fields from string compactifications can lead to long-lived compact objects. Depending on the type of scalar fields we find different realisations of star-like and solitonic objects. We illustrate in the framework of type IIB string compactifications that closed string moduli can lead to heavy microscopic stars with masses of order VαMPlanck, α = 1, 3/2, 5/3 where V is the volume of the extra dimensions. Macroscopic compact objects from ultra-light string axions are realised with masses of order eV 2 / 3MPlanck. Q-ball configurations can be obtained from open string moduli whereas the closed string sector gives rise to a new class of solutions, named PQ-balls, that arise in the two-field axion-modulus system. The stability, the potential for the formation, and the observability of moduli stars through gravitational waves are discussed. In particular we point out that during the early matter phase given by moduli domination, density perturbations grow by a factor Vβ with β > 2 and non-linear effects cannot be neglected.

Original languageEnglish (US)
Article number70
JournalJournal of High Energy Physics
Issue number8
StatePublished - Aug 1 2018


  • Phenomenology of Field Theories in Higher Dimensions
  • Strings and branes phenomenology

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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