Testing <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>H</mml:mi><mml:mn>0</mml:mn></mml:msub></mml:math> in acoustic dark energy models with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>P</mml:mi><mml:mi>l</mml:mi><mml:mi>a</mml:mi><mml:mi>n</mml:mi><mml:mi>c</mml:mi><mml:mi>k</mml:mi></mml:math> and ACT polarization data
Mengxiang Lin, Wayne Hu, Marco Raveri
Abstract
The canonical acoustic dark energy model (cADE), which is based on a scalar field with a canonical kinetic term that rapidly converts potential to kinetic energy around matter radiation equality, alleviates the Hubble tension found in $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$. We show that it successfully passes new consistency tests in the cosmic microwave background (CMB) damping tail provided by the ACT data, while being increasingly constrained and distinguished from alternate mechanisms by the improved CMB acoustic polarization data from $Planck$. The best fit cADE model to a suite of cosmological observations, including the SH0ES ${H}_{0}$ measurement, has ${H}_{0}=70.25$ compared with $68.23\text{ }\text{ }(\mathrm{km}\text{ }{\mathrm{s}}^{\ensuremath{-}1}\text{ }{\mathrm{Mpc}}^{\ensuremath{-}1})$ in $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ and a finite cADE component is preferred at the $2.8\ensuremath{\sigma}$ level. The ability to raise ${H}_{0}$ is now mainly constrained by the improved $Planck$ acoustic polarization data, which also plays a crucial role in distinguishing cADE from the wider class of early dark energy models. Atacama Cosmology Telescope and $Planck$ TE polarization data are currently mildly discrepant in normalization and drive correspondingly different preferences in parameters. Improved constraints on intermediate scale polarization approaching the cosmic variance limit will be an incisive test of the acoustic dynamics of these models and their alternatives.