Indirect limit on the amplitude of primordial gravitational wave background from CMB-galaxy cross correlation

Journal Article · Fri Jul 15 04:00:00 EDT 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.72.023514· OSTI ID:20711117

Cooray, Asantha ^[1]; Corasaniti, Pier-Stefano ^[2]; Giannantonio, Tommaso ^[3]; Melchiorri, Alessandro ^[4]

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1. Department of Physics and Astronomy, University of California, Irvine, California 92697-4575 USA (United States)
2. ISCAP, Columbia University, 550 West 120th Street, New York, New York, 10027 (United States)
3. Dipartimento di Fisica 'G. Marconi', Universita di Roma 'La Sapienza', Ple Aldo Moro 5, 00185, Rome (Italy)
4. Dipartimento di Fisica 'G. Marconi' and INFN, sezione di Roma, Universita' di Roma 'La Sapienza', Ple Aldo Moro 5, 00185, Rome (Italy)

While large scale cosmic microwave background (CMB) anisotropies involve a combination of the scalar and tensor fluctuations, the scalar amplitude can be independently determined through the CMB-galaxy cross correlation. Using recently measured cross correlation amplitudes, arising from the cross correlation between galaxies and the integrated Sachs-Wolfe (ISW) effect in CMB anisotropies, we obtain a constraint r<0.5 at 68% confidence level on the tensor-to-scalar fluctuation amplitude ratio. The data also allow us to exclude gravity waves at a level of a few percent, relative to the density field, in a low-Lambda dominated universe ({omega}{sub {lambda}}{approx}0.5). In future, joining cross correlation ISW measurements, which captures cosmological parameter information, with independent determinations of the matter density and CMB anisotropy power spectrum, may constrain the tensor-to-scalar ratio to a level above 0.05. This value is the ultimate limit on tensor-to-scalar ratio from temperature anisotropy maps when all other cosmological parameters except for the tensor amplitude are known and the combination with CMB-galaxy correlation allows this limit to be reached easily be accounting for degeneracies in certain cosmological parameters.

• OSTI ID: 20711117
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 2 Vol. 72; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANISOTROPY
CORRELATIONS
COSMOLOGY
DENSITY
FLUCTUATIONS
GALAXIES
GRAVITATIONAL WAVES
RELICT RADIATION
SCALARS
TENSORS
UNIVERSE