Optimal weighting in galaxy surveys: Application to redshift-space distortions

Hamaus, Nico; Seljak, Uroš; Desjacques, Vincent

doi:10.1103/physrevd.86.103513

Cited by 46 publications

(59 citation statements)

References 79 publications

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“…(21) of Ref. [37], we can obtain a useful, simple expression for the diagonal Fisher matrix component corresponding to f NL . This quantity is equivalent to the (unmarginalized) signal-to-noise squared of jf NL j ¼ 1 and given by ∂b i ∂f NL ;…”

Section: B Fisher Matrix Forecastsmentioning

confidence: 99%

Designing an inflation galaxy survey: How to measure σ(fNL)∼1 using scale-dependent galaxy bias

Putter

Doré

2017

Phys. Rev. D

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The most promising method for measuring primordial non-Gaussianity in the post-Planck era is to detect large-scale, scale-dependent galaxy bias. Considering the information in the galaxy power spectrum, we here derive the properties of a galaxy clustering survey that would optimize constraints on primordial nonGaussianity using this technique. Specifically, we ask the question of what survey design is needed to reach a precision σðf loc NL Þ ≈ 1. To answer this question, we calculate the sensitivity to f loc NL as a function of galaxy number density, redshift accuracy and sky coverage. We include the multitracer technique, which helps minimize cosmic variance noise, by considering the possibility of dividing the galaxy sample into stellar mass bins. We show that the ideal survey for f loc NL looks very different than most galaxy redshift surveys scheduled for the near future. Since those are more or less optimized for measuring the baryon acoustic oscillation scale, they typically require spectroscopic redshifts. On the contrary, to optimize the f loc NL measurement, a deep, wide, multiband imaging survey is preferred. An uncertainty σðf loc NL Þ ¼ 1 can be reached with a full-sky survey that is complete to an i-band AB magnitude i ≈ 23 and has a number density ∼8 arcmin −2 . Requirements on the multiband photometry are set by a modest photo-z accuracy σðzÞ= ð1 þ zÞ < 0.1 and the ability to measure stellar mass with a precision ∼0.2 dex or better (or another proxy for halo mass with equivalent scatter). Finally, we estimate that for the idealized case of a survey measuring all halos down to a mass 10 10 h −1 M ⊙ on the full sky out to high redshift, in principle a precision of order σðf NL Þ ∼ 0.1 can be achieved.

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Section: B Fisher Matrix Forecastsmentioning

confidence: 99%

Designing an inflation galaxy survey: How to measure σ(fNL)∼1 using scale-dependent galaxy bias

Putter

Doré

2017

Phys. Rev. D

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“…were White et al (2008), McDonald & Seljak (2008) and Hamaus et al (2012). In Abramo (2012), we derived the multi-tracer Fisher directly from the covariance of the counts of the tracers (the "pixel covariance").…”

Section: Multi-tracer Fisher Matrixmentioning

confidence: 99%

Fourier analysis of multitracer cosmological surveys

Abramo

Secco

Loureiro

2015

Mon. Not. R. Astron. Soc.

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We present optimal quadratic estimators for the Fourier analysis of cosmological surveys that detect several different types of tracers of large-scale structure. Our estimators can be used to simultaneously fit the matter power spectrum and the biases of the tracers -as well as redshift-space distortions (RSDs), non-Gaussianities (NGs), or any other effects that are manifested through differences between the clusterings of distinct species of tracers. Our estimators reduce to the one by Feldman, Kaiser & Peacock (ApJ 1994, FKP) in the case of a survey consisting of a single species of tracer. We show that the multi-tracer estimators are unbiased, and that their covariance is given by the inverse of the multi-tracer Fisher matrix (Abramo, MNRAS 2013; Abramo & Leonard, MNRAS 2013). When the biases, RSDs and NGs are fixed to their fiducial values, and one is only interested in measuring the underlying power spectrum, our estimators are projected into the estimator found by Percival, Verde & Peacock (MNRAS 2003). We have tested our estimators on simple (lognormal) simulated galaxy maps, and we show that it performs as expected, being equivalent or superior to the FKP method in all cases we analyzed. Finally, we have shown how to extend the multi-tracer technique to include the 1-halo term of the power spectrum.

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“…Like any galaxy clustering measurement, statistical errors for redshift-space distortion (RSD) come from the combination of sample variance -determined by the finite number of structures present in the survey volume -and shot noise in the measurement of these structures (see §4.4.1). Optimal weighting of galaxies based on their host halo masses can reduce the effects of shot noise below the naive expectation from Poisson statistics Cai and Bernstein, 2012;Hamaus et al, 2012). However, sample variance has a large impact on RSD measurements because filaments and walls extend for many tens of Mpc with specific orientations, so even in real space one would find isotropic clustering only after averaging over many such structures.…”

Section: Redshift-space Distortionsmentioning

confidence: 99%

Observational probes of cosmic acceleration

et al. 2013

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The accelerating expansion of the universe is the most surprising cosmological discovery in many decades, implying that the universe is dominated by some form of "dark energy" with exotic physical properties, or that Einstein's theory of gravity breaks down on cosmological scales. The profound implications of cosmic acceleration have inspired ambitious efforts to understand its origin, with experiments that aim to measure the history of expansion and growth of structure with percent-level precision or higher. We review in detail the four most well established methods for making such measurements: Type Ia supernovae, baryon acoustic oscillations (BAO), weak gravitational lensing, and the abundance of galaxy clusters. We pay particular attention to the systematic uncertainties in these techniques and to strategies for controlling them at the level needed to exploit "Stage IV" dark energy facilities such as BigBOSS, LSST, Euclid, and WFIRST. We briefly review a number of other approaches including redshift-space distortions, the Alcock-Paczynski effect, and direct measurements of the Hubble constant H 0 . We present extensive forecasts for constraints on the dark energy equation of state and parameterized deviations from General Relativity, achievable with Stage III and Stage IV experimental programs that incorporate supernovae, BAO, weak lensing, and cosmic microwave background data. We also show the level of precision required for clusters or other methods to provide constraints competitive with those of these fiducial programs. We emphasize the value of a balanced program that employs several of the most powerful methods in combination, both to cross-check systematic uncertainties and to take advantage of complementary information. Surveys to probe cosmic acceleration produce data sets that support a wide range of scientific investigations, and they continue the longstanding astronomical tradition of mapping the universe in ever greater detail over ever larger scales.

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Optimal weighting in galaxy surveys: Application to redshift-space distortions

Cited by 46 publications

References 79 publications

Designing an inflation galaxy survey: How to measure σ(fNL)∼1 using scale-dependent galaxy bias

Designing an inflation galaxy survey: How to measure σ(fNL)∼1 using scale-dependent galaxy bias

Fourier analysis of multitracer cosmological surveys

Observational probes of cosmic acceleration

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