Constraint on the early Universe by relic gravitational waves: From pulsar timing observations

SEVEN-YEARWILKINSON MICROWAVE ANISOTROPY PROBE(WMAP) OBSERVATIONS: COSMOLOGICAL INTERPRETATION

(2011) E. Komatsu et al.   ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES

Relic gravitational waves: Latest revisions and preparations for new data

(2010) Wen Zhao et al.   PHYSICAL REVIEW D

Constraints upon the spectral indices of relic gravitational waves by LIGO S5

(2010) Y. Zhang et al.   PHYSICAL REVIEW D

An upper limit on the stochastic gravitational-wave background of cosmological origin

(2009)   NATURE

Detecting relic gravitational waves in the CMB: Comparison of different methods

(2009) W. Zhao   PHYSICAL REVIEW D

Relic gravitational waves with a running spectral index and its constraints at high frequencies

(2009) M. L. Tong et al.   PHYSICAL REVIEW D

New method to constrain the relativistic free-streaming gas in the Universe

(2009) Wen Zhao et al.   PHYSICS LETTERS B