%0 Generic %1 hill2021atacama %A Hill, J. Colin %A Calabrese, Erminia %A Aiola, Simone %A Battaglia, Nicholas %A Bolliet, Boris %A Choi, Steve K. %A Devlin, Mark J. %A Duivenvoorden, Adriaan J. %A Dunkley, Jo %A Ferraro, Simone %A Gallardo, Patricio A. %A Gluscevic, Vera %A Hasselfield, Matthew %A Hilton, Matt %A Hincks, Adam D. %A Hlozek, Renee %A Koopman, Brian J. %A Kosowsky, Arthur %A La Posta, Adrien %A Louis, Thibaut %A Madhavacheril, Mathew S. %A McMahon, Jeff %A Moodley, Kavilan %A Naess, Sigurd %A Natale, Umberto %A Nati, Federico %A Newburgh, Laura %A Niemack, Michael D. %A Partridge, Bruce %A Qu, Frank J. %A Salatino, Maria %A Schillaci, Alessandro %A Sehgal, Neelima %A Sherwin, Blake D. %A Sifon, Cristobal %A Spergel, David N. %A Staggs, Suzanne T. %A Storer, Emilie R. %A van Engelen, Alexander %A Vavagiakis, Eve M. %A Wollack, Edward J. %A Xu, Zhilei %D 2021 %K cosmology dark early energy physics %T The Atacama Cosmology Telescope: Constraints on Pre-Recombination Early Dark Energy %U http://arxiv.org/abs/2109.04451 %X The early dark energy (EDE) scenario aims to increase the value of the Hubble constant ($H_0$) inferred from cosmic microwave background (CMB) data over that found in $Łambda$CDM, via the introduction of a new form of energy density in the early universe. The EDE component briefly accelerates cosmic expansion just prior to recombination, which reduces the physical size of the sound horizon imprinted in the CMB. Previous work has found that non-zero EDE is not preferred by Planck CMB power spectrum data alone, which yield a 95% confidence level (CL) upper limit $f_EDE < 0.087$ on the maximal fractional contribution of the EDE field to the cosmic energy budget. In this paper, we fit the EDE model to CMB data from the Atacama Cosmology Telescope (ACT) Data Release 4. We find that a combination of ACT, large-scale Planck TT (similar to WMAP), Planck CMB lensing, and BAO data prefers the existence of EDE at $>99.7$% CL: $f_EDE = 0.091^+0.020_-0.036$, with $H_0 = 70.9^+1.0_-2.0$ km/s/Mpc (both 68% CL). From a model-selection standpoint, we find that EDE is favored over $Łambda$CDM by these data at roughly $3\sigma$ significance. In contrast, a joint analysis of the full Planck and ACT data yields no evidence for EDE, as previously found for Planck alone. We show that the preference for EDE in ACT alone is driven by its TE and EE power spectrum data. The tight constraint on EDE from Planck alone is driven by its high-$\ell$ TT power spectrum data. Understanding whether these differing constraints are physical in nature, due to systematics, or simply a rare statistical fluctuation is of high priority. The best-fit EDE models to ACT and Planck exhibit coherent differences across a wide range of multipoles in TE and EE, indicating that a powerful test of this scenario is anticipated with near-future data from ACT and other ground-based experiments.

@misc{hill2021atacama, abstract = {The early dark energy (EDE) scenario aims to increase the value of the Hubble constant ($H_0$) inferred from cosmic microwave background (CMB) data over that found in $\Lambda$CDM, via the introduction of a new form of energy density in the early universe. The EDE component briefly accelerates cosmic expansion just prior to recombination, which reduces the physical size of the sound horizon imprinted in the CMB. Previous work has found that non-zero EDE is not preferred by Planck CMB power spectrum data alone, which yield a 95% confidence level (CL) upper limit $f_{\rm EDE} < 0.087$ on the maximal fractional contribution of the EDE field to the cosmic energy budget. In this paper, we fit the EDE model to CMB data from the Atacama Cosmology Telescope (ACT) Data Release 4. We find that a combination of ACT, large-scale Planck TT (similar to WMAP), Planck CMB lensing, and BAO data prefers the existence of EDE at $>99.7$% CL: $f_{\rm EDE} = 0.091^{+0.020}_{-0.036}$, with $H_0 = 70.9^{+1.0}_{-2.0}$ km/s/Mpc (both 68% CL). From a model-selection standpoint, we find that EDE is favored over $\Lambda$CDM by these data at roughly $3\sigma$ significance. In contrast, a joint analysis of the full Planck and ACT data yields no evidence for EDE, as previously found for Planck alone. We show that the preference for EDE in ACT alone is driven by its TE and EE power spectrum data. The tight constraint on EDE from Planck alone is driven by its high-$\ell$ TT power spectrum data. Understanding whether these differing constraints are physical in nature, due to systematics, or simply a rare statistical fluctuation is of high priority. The best-fit EDE models to ACT and Planck exhibit coherent differences across a wide range of multipoles in TE and EE, indicating that a powerful test of this scenario is anticipated with near-future data from ACT and other ground-based experiments.}, added-at = {2021-09-24T23:36:23.000+0200}, author = {Hill, J. Colin and Calabrese, Erminia and Aiola, Simone and Battaglia, Nicholas and Bolliet, Boris and Choi, Steve K. and Devlin, Mark J. and Duivenvoorden, Adriaan J. and Dunkley, Jo and Ferraro, Simone and Gallardo, Patricio A. and Gluscevic, Vera and Hasselfield, Matthew and Hilton, Matt and Hincks, Adam D. and Hlozek, Renee and Koopman, Brian J. and Kosowsky, Arthur and La Posta, Adrien and Louis, Thibaut and Madhavacheril, Mathew S. and McMahon, Jeff and Moodley, Kavilan and Naess, Sigurd and Natale, Umberto and Nati, Federico and Newburgh, Laura and Niemack, Michael D. and Partridge, Bruce and Qu, Frank J. and Salatino, Maria and Schillaci, Alessandro and Sehgal, Neelima and Sherwin, Blake D. and Sifon, Cristobal and Spergel, David N. and Staggs, Suzanne T. and Storer, Emilie R. and van Engelen, Alexander and Vavagiakis, Eve M. and Wollack, Edward J. and Xu, Zhilei}, biburl = {https://www.bibsonomy.org/bibtex/290b348e499f28113d13fe18b7b05c41d/droessler}, description = {The Atacama Cosmology Telescope: Constraints on Pre-Recombination Early Dark Energy}, interhash = {25a34e251795b19c60a7dd39a3073a5d}, intrahash = {90b348e499f28113d13fe18b7b05c41d}, keywords = {cosmology dark early energy physics}, note = {cite arxiv:2109.04451Comment: 25+20 pages, 6+18 figures, submitted to PRD}, timestamp = {2021-09-24T23:39:21.000+0200}, title = {The Atacama Cosmology Telescope: Constraints on Pre-Recombination Early Dark Energy}, url = {http://arxiv.org/abs/2109.04451}, year = 2021 }