Multifield curved solid: Early dark energy and perturbation instabilities
arXiv:2402.14108 · doi:10.1103/PhysRevD.109.123539
Abstract
We introduce a multifield dark energy model with a nonflat field-space metric, in which one field is dynamical while the others have constant spatial gradients. The model is predictive at the background level, leading to an early dark energy component at high redshifts and a suppressed fraction of late-time anisotropy. Both features have simple expressions in terms of the curvature scale of the field-space, and correspond to stable points in the phase space of possible solutions. Because of the coupling between time and space-dependent scalar fields, vector field perturbations develop tachyonic instabilities at scales below the Hubble radius, thus being potentially observable in the number count of galaxies. Overall, the presence of a nontrivial field-space curvature also leads to the appearance of instabilities on scalar perturbations, which can impact the matter density distribution at large scales.
10 pages, 3 figures. Minor typo corrected. Matches published version
References in corpus (11)
- Is the Observable Universe Consistent with the Cosmological Principle?
- Perturbations in generalized multi-field inflation
- Theory of cosmological perturbations in an anisotropic universe
- Mass hierarchies and non-decoupling in multi-scalar field dynamics
- Primordial Bispectrum from Multifield Inflation with Nonminimal Couplings
- Creating Statistically Anisotropic and Inhomogeneous Perturbations
- Multi-field dark energy: cosmic acceleration on a steep potential
- Anisotropic solid dark energy
- How can we tell whether dark energy is composed by multiple fields?
- Dark Energy from Inspiraling in Field Space
- Fluctuations of differential number counts of radio continuum sources