title: Atom gravimeters and gravitational redshift.
abstract: In ref. 1 the authors present a re-interpretation of atom interferometry experiments published a decade ago. They now consider the atom interferometry experiments as a measurement of the gravitational redshift on the quantum clock operating at the Compton frequency omega(C) = mc(2)/ approximately 2pi x 3.0 x 10(25) Hz, where m is the caesium (Cs) atom rest mass. They then argue that this redshift measurement compares favourably with existing as well as projected clock tests. Here we show that this interpretation is incorrect.
authors.affiliation: Systèmes de Références Temps Espace, CNRS UMR 8630, Laboratoire National de Métrologie et d'Essais, Université Pierre et Marie Curie, Observatoire de Paris, 61 avenue de l'Observatoire, 75014 Paris, France. peter.wolf@obspm.fr
authors.forename: Peter
authors.initials: P
authors.lastname: Wolf
authors.forename: Luc
authors.initials: L
authors.lastname: Blanchet
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Bordé
authors.forename: Serge
authors.initials: S
authors.lastname: Reynaud
authors.forename: Christophe
authors.initials: C
authors.lastname: Salomon
authors.forename: Claude
authors.initials: C
authors.lastname: Cohen-Tannoudji
references.citation: Phys Rev Lett. 2004 Dec 31;93(26 Pt 1):261101
references.pmid: 15697965
references.citation: Phys Rev Lett. 2008 Feb 1;100(4):041101
references.pmid: 18352252
references.citation: Nature. 2010 Feb 18;463(7283):926-9
references.pmid: 20164925