Document Type
Article
Publication Date
1-13-2025
Published In
Physical Review D
Abstract
Early dark energy, an additional component of dark energy active in the decade of redshift before recombination, has emerged as one of the most effective models at reducing the βπ»β tensionβ between direct measurement of the Hubble parameter π»β in the late Universe and the Ξ CDM prediction when calibrated on Planck. However, it requires a slight increase in the dark matter density πcdm and primordial tilt ππ that worsens the βπβ tensionβ between measurements of weak gravitational lensing at low redshifts and the Planck/Ξβ’CDM prediction. Using a phenomenological fluid model, we investigate whether the inclusion of a drag term between dark matter and early dark energy can compensate for the effect of the increase in power at small-scales, such that both π»β and πβ tensions are simultaneously alleviated. We find that this works if the drag term is dynamically relevant in the post-recombination universe. However, a drag term active before or just around the time at which the early dark energy contribution to the energy density is maximum is significantly constrained due to its impact on the matter perturbations before recombination, and the subsequent modifications to the cosmic microwave background power spectra.
Recommended Citation
T. Simon et al.
(2025).
"Toward alleviating the π»β and πβ tensions with early dark energy-dark matter drag".
Physical Review D.
Volume 111,
DOI: 10.1103/PhysRevD.111.023523
https://works.swarthmore.edu/fac-physics/564
Comments
This work is freely available courtesy of the American Physical Society.