Using the probe brane construction of higher derivative effective field theories, extended to higher co-dimensions and curved spaces, we construct galileon and DBI theories on de Sitter space with N fields and an so (N) internal symmetry, non-linearly realizing the symmetries of a higher dimensional de Sitter space. In some cases, the theory admits a non-trivial vacuum that spontaneously breaks the so (N) symmetry, and around this vacuum the Goldstone modes have vanishing kinetic terms and become infinitely strongly coupled. This gives an example of a scalar effective field theory with two de Sitter vacua, one of which appears to have Boulware-Deser-like ghosts, and one of which does not.
Garoffolo, Alice, et al. "Multi-Galileons in curved space." Journal of High Energy Physics (Online), vol. 2025, no. 9, Sep. 2025. https://doi.org/10.1007/JHEP09(2025)115
Garoffolo, Alice, Hinterbichler, Kurt, & Trodden, Mark (2025). Multi-Galileons in curved space. Journal of High Energy Physics (Online), 2025(9). https://doi.org/10.1007/JHEP09(2025)115
Garoffolo, Alice, Hinterbichler, Kurt, and Trodden, Mark, "Multi-Galileons in curved space," Journal of High Energy Physics (Online) 2025, no. 9 (2025), https://doi.org/10.1007/JHEP09(2025)115
@article{osti_3011548,
author = {Garoffolo, Alice and Hinterbichler, Kurt and Trodden, Mark},
title = {Multi-Galileons in curved space},
annote = {Using the probe brane construction of higher derivative effective field theories, extended to higher co-dimensions and curved spaces, we construct galileon and DBI theories on de Sitter space with N fields and an so (N) internal symmetry, non-linearly realizing the symmetries of a higher dimensional de Sitter space. In some cases, the theory admits a non-trivial vacuum that spontaneously breaks the so (N) symmetry, and around this vacuum the Goldstone modes have vanishing kinetic terms and become infinitely strongly coupled. This gives an example of a scalar effective field theory with two de Sitter vacua, one of which appears to have Boulware-Deser-like ghosts, and one of which does not.},
doi = {10.1007/JHEP09(2025)115},
url = {https://www.osti.gov/biblio/3011548},
journal = {Journal of High Energy Physics (Online)},
issn = {ISSN 1029-8479},
number = {9},
volume = {2025},
place = {United States},
publisher = {Springer Nature},
year = {2025},
month = {09}}
Proceedings of Corfu Summer Institute 2021 "School and Workshops on Elementary Particle Physics and Gravity" — PoS(CORFU2021)https://doi.org/10.22323/1.406.0356