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Cosmic rulers

Schmidt, Fabian and Jeong, Donghui (2012) Cosmic rulers. Physical Review D, 86 (8). Art. No. 083527 . ISSN 2470-0010. doi:10.1103/PhysRevD.86.083527.

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We derive general covariant expressions for the six independent observable modes of distortion of ideal standard rulers in a perturbed Friedmann-Robertson-Walker spacetime. Our expressions are gauge invariant and valid on the full sky. These six modes are most naturally classified in terms of their rotational properties on the sphere, yielding two scalars, two vector (spin-1), and two tensor (spin-2) components. One scalar corresponds to the magnification, while the spin-2 components correspond to the shear. The vector components allow for a polar/axial decomposition analogous to the E/B decomposition for the shear. Scalar modes do not contribute to the axial (B-)vector, opening a new avenue to probing tensor modes. Our results apply, but are not limited to, the distortion of correlation functions (of the cosmic microwave background, 21-cm emission, or galaxies) as well as to weak lensing shear and magnification, all of which can be seen as methods relying on "standard rulers."

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Additional Information:© 2012 American Physical Society. Received 10 May 2012; published 15 October 2012. We would like to thank Yanbei Chen, Scott Dodelson, Olivier Doré, Sam Gralla, Chris Hirata, Wayne Hu, Bhuvnesh Jain, Marc Kamionkowski, Eiichiro Komatsu, David Nichols, and Samaya Nissanke for helpful discussions. F. S. thanks Masahiro Takada and the Kavli-IPMU, University of Tokyo, for hospitality. F. S. is supported by the Gordon and Betty Moore Foundation at Caltech.
Group:Moore Center for Theoretical Cosmology and Physics
Funding AgencyGrant Number
Gordon and Betty Moore FoundationUNSPECIFIED
Issue or Number:8
Classification Code:PACS: 98.80.Jk, 98.65.-r, 98.65.Dx
Record Number:CaltechAUTHORS:20121116-093009806
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:35506
Deposited By: Tony Diaz
Deposited On:20 Nov 2012 17:23
Last Modified:09 Nov 2021 23:15

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