The atacama cosmology telescope: A measurement of the primordial power spectrum

Renée Hlozek, Joanna Dunkley, Graeme Addison, John William Appel, J. Richard Bond, C. Sofia Carvalho, Sudeep Das, Mark J. Devlin, Rolando Dünner, Thomas Essinger-Hileman, Joseph W. Fowler, Patricio Gallardo, Amir Hajian, Mark Halpern, Matthew Hasselfield, Matt Hilton, Adam D. Hincks, John P. Hughes, Kent D. Irwin, Jeff KleinArthur Kosowsky, Tobias A. Marriage, Danica Marsden, Felipe Menanteau, Kavilan Moodley, Michael D. Niemack, Michael R. Nolta, Lyman A. Page, Lucas Parker, Bruce Partridge, Felipe Rojas, Neelima Sehgal, Blake Sherwin, Jon Sievers, David N. Spergel, Suzanne T. Staggs, Daniel S. Swetz, Eric R. Switzer, Robert Thornton, Ed Wollack

Research output: Contribution to journalArticlepeer-review

96 Scopus citations


We present constraints on the primordial power spectrum of adiabatic fluctuations using data from the 2008 Southern Survey of the Atacama Cosmology Telescope (ACT) in combination with measurements from the Wilkinson Microwave Anisotropy Probe and a prior on the Hubble constant. The angular resolution of ACT provides sensitivity to scales beyond ℓ = 1000 for resolution of multiple peaks in the primordial temperature power spectrum, which enables us to probe the primordial power spectrum of adiabatic scalar perturbations with wavenumbers up to k ≃ 0.2Mpc-1. We find no evidence for deviation from power-law fluctuations over two decades in scale. Matter fluctuations inferred from the primordial temperature power spectrum evolve over cosmic time and can be used to predict the matter power spectrum at late times; we illustrate the overlap of the matter power inferred from cosmic microwave background measurements (which probe the power spectrum in the linear regime) with existing probes of galaxy clustering, cluster abundances, and weak-lensing constraints on the primordial power. This highlights the range of scales probed by current measurements of the matter power spectrum.

Original languageEnglish (US)
Article number90
JournalAstrophysical Journal
Issue number1
StatePublished - Apr 10 2012

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • cosmic background radiation
  • cosmology: observations
  • cosmology: theory
  • inflation


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