scholarly journals Testing the equivalence principle on cosmological scales using the odd multipoles of galaxy cross-power spectrum and bispectrum

2021 ◽  
Vol 2021 (08) ◽  
pp. 049
Author(s):  
Obinna Umeh ◽  
Kazuya Koyama ◽  
Robert Crittenden
Keyword(s):  
Power Spectrum ◽  
Equivalence Principle ◽  
Cross Power Spectrum

scholarly journals The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: a multitracer analysis in Fourier space for measuring the cosmic structure growth and expansion rate

2021 ◽  
Vol 504 (1) ◽  
pp. 33-52
Author(s):  
Gong-Bo Zhao ◽  
Yuting Wang ◽  
Atsushi Taruya ◽  
Weibing Zhang ◽  
Héctor Gil-Marín ◽  
...  
Keyword(s):  
Growth Rate ◽  
Power Spectrum ◽  
Confidence Level ◽  
Expansion Rate ◽  
Fourier Space ◽  
Redshift Range ◽  
Significance Level ◽  
Data Product ◽  
New Development ◽  
Cross Power Spectrum

ABSTRACT We perform a joint BAO and RSD analysis using the eBOSS DR16 LRG and ELG samples in the redshift range of z ∈ [0.6, 1.1], and detect an RSD signal from the cross-power spectrum at a ∼4σ confidence level, i.e., fσ8 = 0.317 ± 0.080 at zeff = 0.77. Based on the chained power spectrum, which is a new development in this work to mitigate the angular systematics, we measure the BAO distances and growth rate simultaneously at two effective redshifts, namely, DM/rd (z = 0.70) = 17.96 ± 0.51, DH/rd (z = 0.70) = 21.22 ± 1.20, fσ8 (z = 0.70) = 0.43 ± 0.05, and DM/rd (z = 0.845) = 18.90 ± 0.78, DH/rd (z = 0.845) = 20.91 ± 2.86, fσ8 (z = 0.845) = 0.30 ± 0.08. Combined with BAO measurements including those from the eBOSS DR16 QSO and Lyman-α sample, our measurement has raised the significance level of a non-zero ΩΛ to ∼11σ. The data product of this work is publicly available at https://github.com/icosmology/eBOSS_DR16_LRGxELG and https://www.sdss.org/science/final-bao-and-rsd-measurements/.

THE COVARIANCE OF EXTERNAL SHOT NOISE AT A SENSOR ARRAY

Geophysics ◽  
1973 ◽  
Vol 38 (5) ◽  
pp. 957-958
Author(s):  
T. S. Edrington
Keyword(s):  
Power Spectrum ◽  
Bessel Function ◽  
Shot Noise ◽  
Sensor Array ◽  
Random Noise ◽  
Zero Order ◽  
Random Combination ◽  
Order Bessel Function ◽  
Single Sensor ◽  
Cross Power Spectrum

Noise (of seismic and other origins) is often modeled as a shot process, i.e., as a random combination of wavelets. Specifically, if X is the random noise process and g is the deterministic waveform of the wavelet, then [Formula: see text]where the [Formula: see text] are Poisson points in time. One useful result (derived by Backus et al., 1964) under this model is that if the wavelets are propagating across a sensor array, and if the wavelet origins are uniformly distributed in azimuth, then the cross‐power spectrum for a pair of sensors is the product of the power spectrum at a single sensor and a zero‐order Bessel function. In the notation of Backus et al., [Formula: see text]

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