J. D. F. Dias, N. Schöneberg, L. Vacher, C. J. A. P. Martins, S. Vinzl
Abstract
The rolling tachyon is a non-canonical scalar field model well motivated in string theory which naturally predicts variations of the fine-structure constant. Such variations can in principle lead to interesting observable consequences, but they can also lead to extremely tight constraints on these kinds of models. In this work we subject the rolling tachyon model evolving in a variety of potentials to current data and show that most cosmologically interesting evolutions are already strongly excluded. We find |1 + w0| < 10-3 from cosmological data and |1 + w0| < 10-9 from fine-structure data, leaving the rolling tachyon to either play a role almost entirely equivalent to a cosmological constant or that of a test field. We also find that in most of the allowed parameter space the field evolves very slowly, allowing its evolution to be approximated as an equivalent canonical scalar field.
Keywords
cosmology of theories beyond the SM, dark energy theory, quantum gravity phenomenology, string theory and cosmology
Journal of Cosmology and Astroparticle Physics
Volume 11, Issue 030, Page 30
2024 November
