arXiv subjects

Ken Osato

Publications and source records attributed to Ken Osato.

At least 55 records · Page 3Linked to original sources

arXiv2021

Third Data Release of the Hyper Suprime-Cam Subaru Strategic Program

The paper presents the third data release of Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP), a wide-field multi-band imaging survey with the Subaru 8.2m telescope. HSC-SSP has three survey layers (Wide, Deep, and UltraDeep) with different area coverages and depths, designed to address a wide array of astrophysical questions. This third release from HSC-SSP includes data from 278 nights of observing time and covers about 670 square degrees in all five broad-band filters at the full depth ($\sim26$~mag at $5σ$) in the Wide layer. If we include partially observed area, the release covers 1,470 square degrees. The Deep and UltraDeep layers have $\sim80\%$ of the originally planned integration times, and are considered done, as we have slightly changed the observing strategy in order to compensate for various time losses. There are a number of updates in the image processing pipeline. Of particular importance is the change in the sky subtraction algorithm; we subtract the sky on small scales before the detection and measurement stages, which has significantly reduced false detections. Thanks to this and other updates, the overall quality of the processed data has improved since the previous release. However, there are limitations in the data (for example, the pipeline is not optimized for crowded fields), and we encourage the user to check the quality assurance plots as well as a list of known issues before exploiting the data. The data release website is https://hsc-release.mtk.nao.ac.jp/.

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arXiv2021

An Optimal Estimator of Intrinsic Alignments for Star-forming Galaxies in IllustrisTNG Simulation

Emission line galaxies (ELGs), more generally star-forming galaxies, are valuable tracers of large-scale structure and therefore main targets of upcoming wide-area spectroscopic galaxy surveys. We propose a fixed-aperture shape estimator of each ELG for extracting the intrinsic alignment (IA) signal, and assess the performance of the method using image simulations of ELGs generated from the IllustrisTNG simulation including observational effects such as the sky background noise. We show that our method enables a significant detection of the IA power spectrum with the linear-scale coefficient $A_{\rm IA}\simeq (13$--$15)\pm 3.0$ up to $z=2$, even from the small simulation volume $\sim0.009\,(h^{-1}{\rm Gpc})^3$, in contrast to the null detection with the standard method. Thus the ELG IA signal, measured with our method, opens up opportunities to exploit cosmology and galaxy physics in high-redshift universe.

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arXiv2021

Angular clustering and host halo properties of [OII] emitters at $z >1$ in the Subaru HSC survey

We study the angular correlation function of star-forming galaxies and properties of their host dark matter halos at z>1 using the Hyper-Suprime Cam (HSC) SSP survey. We use [OII] emitters identified using two narrow-band (NB) filters, NB816 and NB921, in the Deep/UltraDeep layers, which respectively cover large angular areas of 16.3 deg^2 and 16.9 deg^2. Our sample contains 8302 and 9578 [OII] emitters at z=1.19 (NB816) and z=1.47 (NB921), respectively. We detect a strong clustering signal over a wide angular range, 0.001 < θ< 1 [deg], with the bias $b=1.61^{+0.13}_{-0.11}$ (z=1.19) and $b=2.09^{+0.17}_{-0.15}$ (z=1.47). We also find a clear deviation of the correlation from a simple power-law form. To interpret the measured clustering signal, we adopt a halo occupation distribution (HOD) model that is constructed to explain the spatial distribution of galaxies selected by a star formation rate. The observed correlation function and number density are simultaneously explained by the best-fitting HOD model. From the constrained HOD model, the average mass of halos hosting the [OII] emitters is derived to be $\log{M_{eff}/(h^{-1}M_\odot)}=12.70^{+0.09}_{-0.07}$ and $12.61^{+0.09}_{-0.05}$ at z=1.19 and 1.47, respectively, which will become halos with the present-day mass, $M\sim 1.5 \times 10^{13}h^{-1}M_\odot$. The satellite fraction of the [OII] emitter sample is found to be $f_{sat}\sim 0.15$. All these values are consistent with the previous studies of similar samples, but we obtain tighter constraints even in a larger parameter space due to the larger sample size from the HSC. The results obtained for host halos of [OII] emitters in this paper enable the construction of mock galaxy catalogs and the systematic forecast study of cosmological constraints from upcoming emission line galaxy surveys such as the Subaru PFS survey.

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arXiv2021

$κ$TNG: Effect of Baryonic Processes on Weak Lensing with IllustrisTNG Simulations

We study the effect of baryonic processes on weak lensing (WL) observables with a suite of mock WL maps, the $κ$TNG, based on the cosmological hydrodynamic simulations IllustrisTNG. We quantify the baryonic effects on the WL angular power spectrum, one-point probability distribution function (PDF), and number counts of peaks and minima. We also show the redshift evolution of the effects, which is a key to distinguish the effect of baryons from fundamental physics such as dark energy, dark matter, and massive neutrinos. We find that baryonic processes reduce the small-scale power, suppress the tails of the PDF, peak and minimum counts, and change the total number of peaks and minima. We compare our results to existing semi-analytic models and hydrodynamic simulations, and discuss the source of discrepancies. The $κ$TNG suite includes 10,000 realisations of $5 \times 5 \, \mathrm{deg}^2$ maps for 40 source redshifts up to $z_s = 2.6$, well covering the range of interest for existing and upcoming weak lensing surveys. We also produce the $κ$TNG-Dark suite of maps, generated based on the corresponding dark matter only IllustrisTNG simulations. Our mock maps are suitable for developing analytic models that incorporate the effect of baryons, but also particularly useful for studies that rely on mass maps, such as non-Gaussian statistics and machine learning with convolutional neural networks. The suite of mock maps is publicly available at Columbia Lensing (http://columbialensing.org).

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arXiv2021

Super-sample covariance of the thermal Sunyaev-Zel'dovich effect

The thermal Sunyaev-Zel'dovich (tSZ) effect is a powerful probe of cosmology. The statistical errors in the tSZ power spectrum measurements are dominated by the presence of massive clusters in a survey volume that are easy to identify on individual cluster basis. First, we study the impact of super sample covariance (SSC) on the tSZ power spectrum measurements, and find that the sample variance is dominated by the connected non-Gaussian (cNG) covariance arising mainly from Poisson number fluctuations of massive clusters in the survey volume. Second, we find that removing such individually-detected, massive clusters from the analysis significantly reduces the cNG contribution, thereby leading the SSC to be a leading source of the sample variance. We then show, based on Fisher analysis, that the power spectrum measured from the remaining diffuse tSZ effects can be used to obtain tight constraints on cosmological parameters as well as the hydrostatic mass bias parameter. Our method offers complementary use of individual tSZ cluster counts and the power spectrum measurements of diffuse tSZ signals for cosmology and intracluster gas physics.

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arXiv2021

Power Spectrum of Intrinsic Alignments of Galaxies in IllustrisTNG

We present the 3-{\it dimensional} intrinsic alignment power spectra between the projected 2d galaxy shape/spin and the 3d tidal field across $0.1<k/h{\rm Mpc}^{-1}<60$ using cosmological hydrodynamical simulation, Illustris-TNG300, at redshifts ranging from $0.3$ to $2$. The shape-tidal field alignment increases with galaxy mass and the linear alignment coefficient $A_{\rm IA}$, defined with respect to the primordial tidal field, is found to have weak redshift dependence. We also show a promising detection of the shape/spin-tidal field alignments for stellar mass limited samples and a weak or almost null signal for star-forming galaxies for the TNG300 volume, $\sim 0.01~(h^{-1}{\rm Gpc})^3$. We further study the morphology and environmental dependence of the intrinsic alignment power spectra. The shape of massive disk- and spheroid-galaxies tend to align with the tidal field. The spin of low mass disks (and spheroids at low redshifts) tend to be parallel with the tidal field, while the spin of massive spheroids and disks tend to be perpendicular to tidal field. The shape and spin of massive centrals align with the tidal field at both small and large scales. Satellites show a radial alignment within the one-halo term region, and low mass satellites have an intriguing alignment signal in the two-halo term region. We also forecast a feasibility to measure the intrinsic alignment power spectrum for spectroscopic and imaging surveys such as Subaru HSC/PFS and DESI. Our results thus suggest that galaxy intrinsic alignment can be used as a promising tool for constraining the galaxy formation models.

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arXiv2020

Cosmological inference from emulator based halo model I: Validation tests with HSC and SDSS mock catalogs

We present validation tests of emulator-based halo model method for cosmological parameter inference, assuming hypothetical measurements of the projected correlation function of galaxies, $w_{\rm p}(R)$, and the galaxy-galaxy weak lensing, $Δ\!Σ(R)$, from the spectroscopic SDSS galaxies and the Hyper Suprime-Cam Year1 (HSC-Y1) galaxies. To do this, we use \textsc{Dark Emulator} developed in Nishimichi et al. based on an ensemble of $N$-body simulations, which is an emulation package enabling a fast, accurate computation of halo clustering quantities for flat-geometry $w$CDM cosmologies. Adopting the halo occupation distribution, the emulator allows us to obtain model predictions of $Δ\!Σ$ and $w_{\rm p}$ for the SDSS-like galaxies at a few CPU seconds for an input set of parameters. We present performance and validation of the method by carrying out Markov Chain Monte Carlo analyses of the mock signals measured from a variety of mock catalogs that mimic the SDSS and HSC-Y1 galaxies. We show that the halo model method can recover the underlying true cosmological parameters to within the 68\% credible interval, except for the mocks including the assembly bias effect (although we consider the unrealistically-large amplitude of assembly bias effect). Even for the assembly bias mock, we demonstrate that the cosmological parameters can be recovered {\it if} the analysis is restricted to scales $R\gtrsim 10~h^{-1}{\rm Mpc}$. We also show that, by using a single population of source galaxies to infer the relative strengths of $Δ\!Σ$ for multiple lens samples at different redshifts, the joint probes method allows for self-calibration of photometric redshift errors and multiplicative shear bias. Thus we conclude that the emulator-based halo model method can be safely applied to the HSC-Y1 dataset, achieving a precision of $σ(S_8)\simeq 0.04$.

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arXiv2020

Power spectrum of halo intrinsic alignments in simulations

We use a suite of $N$-body simulations to study intrinsic alignments (IA) of halo shapes with the surrounding large-scale structure in the $Λ$CDM model. For this purpose, we develop a novel method to measure multipole moments of the three-dimensional power spectrum of the $E$-mode field of halo shapes with the matter/halo distribution, $P_{δE}^{(\ell)}(k)$ (or $P^{(\ell)}_{{\rm h}E}$), and those of the auto-power spectrum of the $E$ mode, $P^{(\ell)}_{EE}(k)$, based on the $E$/$B$-mode decomposition. The IA power spectra have non-vanishing amplitudes over the linear to nonlinear scales, and the large-scale amplitudes at $k\lesssim 0.1~h~{\rm Mpc}^{-1}$ are related to the matter power spectrum via a constant coefficient ($A_{\rm IA}$), similar to the linear bias parameter of galaxy or halo density field. We find that the cross- and auto-power spectra $P_{δE}$ and $P_{EE}$ at nonlinear scales, $k\gtrsim 0.1~h~{\rm Mpc}^{-1}$, show different $k$-dependences relative to the matter power spectrum, suggesting a violation of the nonlinear alignment model commonly used to model contaminations of cosmic shear signals. The IA power spectra exhibit baryon acoustic oscillations, and vary with halo samples of different masses, redshifts and cosmological parameters ($Ω_{\rm m}, S_8$). The cumulative signal-to-noise ratio for the IA power spectra is about 60% of that for the halo density power spectrum, where the super-sample covariance is found to give a significant contribution to the total covariance. Thus our results demonstrate that the IA power spectra of galaxy shapes, measured from imaging and spectroscopic surveys for an overlapping area of the sky, can be used to probe the underlying matter power spectrum, the primordial curvature perturbations, and cosmological parameters, in addition to the standard galaxy density power spectrum.

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arXiv2020

Accurate emulator for the redshift-space power spectrum of dark matter halos and its application to galaxy power spectrum

An accurate theoretical template of the redshift-space galaxy power spectrum, if applicable out to nonlinear scales, enables us to extract more stringent and robust constraints on cosmological parameters from the measured galaxy clustering. In this work, we develop a simulation-based template, so-called emulator, for the redshift-space power spectrum of dark matter halos. Using the redshift-space halo power spectra measured from the Dark Quest $N$-body simulation suite that covers 101 flat-geometry $w$CDM cosmologies around the Planck $Λ$CDM model, we feed these data into a feed-forward neural network to build the fast and accurate emulation of the power spectrum from the linear to nonlinear scales up to $k \simeq 0.6 \,h \,{\rm Mpc}^{-1}$. Our emulator achieves about 1% and 5% fractional accuracies in predicting the monopole and quadrupole moments of the power spectrum, respectively, for halos of $\sim 10^{13}h^{-1}M_\odot$ that correspond to host halos of the SDSS LOWZ- and CMASS-like galaxies, where the achieved accuracies are sufficient compared to the statistical errors of SDSS volume. The validation and performance of the emulator are given by the comparison of the emulator predictions with the power spectra directly measured from the simulations for validation sets that are not used in the training. We demonstrate that the emulator outputs can be used to make model predictions for the redshift-space power spectrum of galaxies by employing user-fed models for the halo-galaxy connection, such as the halo occupation distribution. The emulator allows us to easily incorporate the Finger-of-God effect due to the virial motions of galaxies and the Alcock-Paczyński distortions. Our code can compute the redshift-space galaxy power spectrum in a CPU subseconds and is ready to perform the emulator-based cosmological analysis for the exiting and upcoming galaxy redshift surveys.

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arXiv2020

The impact of projection effects on cluster observables: stacked lensing and projected clustering

An optical cluster finder inevitably suffers from projection effects, where it misidentifies a superposition of galaxies in multiple halos along the line-of-sight as a single cluster. Using mock cluster catalogs built from cosmological N-body simulations, we quantify the impact of these projection effects with a particular focus on the observables of interest for cluster cosmology, namely the cluster lensing and the cluster clustering signals. We find that "observed" clusters, i.e. clusters identified by our cluster finder algorithm, exhibit lensing and clustering signals that deviate from expectations based on a statistically isotropic halo model -- while both signals agree with halo model expectations on small scales, they show unexpected boosts on large scales, by up to a factor of 1.2 or 1.4 respectively. We identify the origin of these boosts as the inherent selection bias of optical cluster finders for clusters embedded within filaments aligned with the line-of-sight, and show that a minority ($\sim 30\%$) of such clusters within the entire sample is responsible for this observed boost. We discuss the implications of our results on previous studies of optical cluster, as well as prospects for identifying and mitigating projection effects in future cluster cosmology analyses.

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arXiv2020

Fitting the nonlinear matter bispectrum by the Halofit approach

We provide a new fitting formula of the matter bispectrum in the nonlinear regime calibrated by high-resolution cosmological $N$-body simulations of $41$ cold dark matter ($w$CDM, $w=$ constant) models around the Planck 2015 best-fit parameters. As the parameterization in our fitting function is similar to that in Halofit, our fitting is named BiHalofit. The simulation volume is sufficiently large ($> 10 \, {\rm Gpc}^3$) to cover almost all measurable triangle bispectrum configurations in the universe. The function is also calibrated using one-loop perturbation theory at large scales ($k<0.3 \, h \, {\rm Mpc}^{-1}$). Our formula reproduced the matter bispectrum to within $10 \, (15) \, \%$ accuracy in the Planck 2015 model at wavenumber $k< 3 \, (10) \, h \, {\rm Mpc}^{-1}$ and redshifts $z=0-3$. The other $40$ $w$CDM models obtained poorer fits, with accuracy approximating $20 \, \%$ at $k<3 \, h \, {\rm Mpc}^{-1}$ and $z=0-1.5$ (the deviation includes the $10 \, \%$-level sample variance of the simulations). We also provide a fitting formula that corrects the baryonic effects such as radiative cooling and active galactic nucleus feedback, using the latest hydrodynamical simulation IllustrisTNG. We demonstrate that our new formula more accurately predicts the weak-lensing bispectrum than the existing fitting formulas. This formula will assist current and future weak-lensing surveys and cosmic microwave background lensing experiments. Numerical codes of the formula are available, written in Python, C and Fortran.

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arXiv2020

The splashback radius of optically selected clusters with Subaru HSC Second Public Data Release

Recent constraints on the splashback radius around optically selected galaxy clusters from the redMaPPer cluster-finding algorithm in the literature have shown that the observed splashback radius is $\sim 20\%$ smaller than that predicted by N-body simulations. We present analyses on the splashback features around $\sim 3000$ optically selected galaxy clusters detected by the independent cluster-finding algorithm CAMIRA over a wide redshift range of $0.1<z_{\rm cl}<1.0$ from the second public data release of the Hyper Suprime-Cam (HSC) Subaru Strategic Program covering $\sim 427~{\rm deg}^2$ for the cluster catalog. We detect the splashback feature from the projected cross-correlation measurements between the clusters and photometric galaxies over the wide redshift range, including for high redshift clusters at $0.7<z_{\rm cl}<1.0$, thanks to deep HSC images. We find that constraints from red galaxy populations only are more precise than those without any color cut, leading to $1σ$ precisions of $\sim 15\%$ at $0.4<z_{\rm cl}<0.7$ and $0.7<z_{\rm cl}<1.0$. These constraints are more consistent with the model predictions ($\lesssim 1σ$) than their $20\%$ smaller values as suggested by the previous studies with the redMaPPer ($\sim 2σ$). We also investigate selection effects of the optical cluster-finding algorithms on the observed splashback features by creating mock galaxy catalogs from a halo occupation distribution model, and find that such effects to be sub-dominant for the CAMIRA cluster-finding algorithm. We also find that the redMaPPer-like cluster-finding algorithm induces a smaller inferred splashback radius in our mock catalog, especially at lower richness, which can well explain the smaller splashback radii in the literature. In contrast, these biases are significantly reduced when increasing its aperture size.

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arXiv2020

Cross-correlation of the thermal Sunyaev-Zel'dovich effect and weak gravitational lensing: Planck and Subaru Hyper Suprime-Cam first-year data

Cross-correlation analysis of the thermal Sunyaev-Zel'dovich (tSZ) effect and weak gravitational lensing (WL) provides a powerful probe of cosmology and astrophysics of the intra-cluster medium. We present the measurement of the cross-correlation of tSZ and WL from Planck and Subaru Hyper-Suprime Cam. The combination enables us to study cluster astrophysics at high redshift. We use the tSZ-WL cross-correlation and the tSZ auto-power spectrum measurements to place a tight constraint on the hydrostatic mass bias, which is a measure of the degree of non-thermal pressure support in galaxy clusters. With the prior on cosmological parameters derived from the analysis of the cosmic microwave background anisotropies by Planck and taking into account foreground contributions both in the tSZ auto-power spectrum and the tSZ-WL cross-correlation, the hydrostatic mass bias is estimated to be $26.9^{+8.9}_{-4.4} \%$ ($68\%$ C.L.), which is consistent with recent measurements by mass calibration techniques.

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arXiv2019

Weak Lensing Minima and Peaks: Cosmological Constraints and the Impact of Baryons

We present a novel statistic to extract cosmological information in weak lensing data: the lensing minima. We also investigate the effect of baryons on the cosmological constraints from peak and minimum counts. Using the \texttt{MassiveNuS} simulations, we find that lensing minima are sensitive to non-Gaussian cosmological information and are complementary to the lensing power spectrum and peak counts. For an LSST-like survey, we obtain $95\%$ credible intervals from a combination of lensing minima and peaks that are significantly stronger than from the power spectrum alone, by $44\%$, $11\%$, and $63\%$ for the neutrino mass sum $\sum m_ν$, matter density $Ω_m$, and amplitude of fluctuation $A_s$, respectively. We explore the effect of baryonic processes on lensing minima and peaks using the hydrodynamical simulations \texttt{BAHAMAS} and \texttt{Osato15}. We find that ignoring baryonic effects would lead to strong ($\approx 4 σ$) biases in inferences from peak counts, but negligible ($\approx 0.5 σ$) for minimum counts, suggesting lensing minima are a potentially more robust tool against baryonic effects. Finally, we demonstrate that the biases can in principle be mitigated without significantly degrading cosmological constraints when we model and marginalize the baryonic effects.

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arXiv2019

Second Data Release of the Hyper Suprime-Cam Subaru Strategic Program

This paper presents the second data release of the Hyper Suprime-Cam Subaru Strategic Program, a wide-field optical imaging survey on the 8.2 meter Subaru Telescope. The release includes data from 174 nights of observation through January 2018. The Wide layer data cover about 300 deg^2 in all five broadband filters (grizy) to the nominal survey exposure (10min in gr and 20min in izy). Partially observed areas are also included in the release; about 1100 deg^2 is observed in at least one filter and one exposure. The median seeing in the i-band is 0.6 arcsec, demonstrating the superb image quality of the survey. The Deep (26 deg^2) and UltraDeep (4 deg^2) data are jointly processed and the UltraDeep-COSMOS field reaches an unprecedented depth of i~28 at 5 sigma for point sources. In addition to the broad-bands, narrow-band data are also available in the Deep and UltraDeep fields. This release includes a major update to the processing pipeline, including improved sky subtraction, PSF modeling, object detection, and artifact rejection. The overall data quality has been improved, but this release is not without problems; there is a persistent deblender problem as well as new issues with masks around bright stars. The user is encouraged to review the issue list before utilizing the data for scientific explorations. All the image products as well as catalog products are available for download. The catalogs are also loaded to a database, which provides an easy interface for users to retrieve data for objects of interest. In addition to these main data products, detailed galaxy shape measurements withheld from the Public Data Release 1 (PDR1) are now available to the community. The shape catalog is drawn from the S16A internal release, which has a larger area than PDR1 (160 deg^2). All products are available at the data release site, https://hsc-release.mtk.nao.ac.jp/.

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arXiv2019

The mass-richness relation of optically-selected clusters from weak gravitational lensing and abundance with Subaru HSC first-year data

Constraining the relation between the richness $N$ and the halo mass $M$ over a wide redshift range for optically-selected clusters is a key ingredient for cluster-related science in optical surveys, including the Subaru Hyper Suprime-Cam (HSC) survey. We measure stacked weak lensing profiles around 1747 HSC CAMIRA clusters over a redshift range of $0.1\leq z_{\rm cl}\leq 1.0$ with $N\geq 15$ using the HSC first-year shear catalog covering $\sim$$140$ ${\rm deg^2}$. The exquisite depth and image quality of the HSC survey allow us to measure lensing signals around the high-redshift clusters at $0.7\leq z_{\rm cl}\leq 1.0$ with a signal-to-noise ratio of 19 in the comoving radius range $0.5\lesssim R\lesssim 15 h^{-1}{\rm Mpc}$. We constrain richness-mass relations $P(\ln N|M,z)$ of the HSC CAMIRA clusters assuming a log-normal distribution without informative priors on model parameters, by jointly fitting to the lensing profiles and abundance measurements under both Planck and WMAP cosmological models. We show that our model gives acceptable $p$-values when we add redshift dependent terms which are proportional to $\ln (1+z)$ and $[\ln (1+z)]^{2}$ into the mean and scatter relations of $P(\ln N|M,z)$. Such terms presumably originate from the variation of photometric redshift errors as a function of the redshift. We show that the constraints on the mean relation $\langle M|N \rangle$ are consistent between the Planck and WMAP models, whereas the scatter values $σ_{\ln M|N}$ for the Planck model are systematically larger than those for the WMAP model. We also show that the scatter values for the Planck model increase toward lower richness values, whereas those for the WMAP model are consistent with constant values as a function of richness. This result highlights the importance of the scatter in the mass-richness relation for cluster cosmology.

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arXiv2019

Dark Quest. I. Fast and Accurate Emulation of Halo Clustering Statistics and Its Application to Galaxy Clustering

We perform an ensemble of $N$-body simulations with $2048^3$ particles for 101 flat $w$CDM cosmological models sampled based on a maximin-distance Sliced Latin Hypercube Design. By using the halo catalogs extracted at multiple redshifts in the range of $z=[0,1.48]$, we develop Dark Emulator, which enables fast and accurate computations of the halo mass function, halo-matter cross-correlation, and halo auto-correlation as a function of halo masses, redshift, separations and cosmological models, based on the Principal Component Analysis and the Gaussian Process Regression for the large-dimensional input and output data vector. We assess the performance of the emulator using a validation set of $N$-body simulations that are not used in training the emulator. We show that, for typical halos hosting CMASS galaxies in the Sloan Digital Sky Survey, the emulator predicts the halo-matter cross correlation, relevant for galaxy-galaxy weak lensing, with an accuracy better than $2\%$ and the halo auto-correlation, relevant for galaxy clustering correlation, with an accuracy better than $4\%$. We give several demonstrations of the emulator. It can be used to study properties of halo mass density profiles such as the mass-concentration relation and splashback radius for different cosmologies. The emulator outputs can be combined with an analytical prescription of halo-galaxy connection such as the halo occupation distribution at the equation level, instead of using the mock catalogs, to make accurate predictions of galaxy clustering statistics such as the galaxy-galaxy weak lensing and the projected correlation function for any model within the $w$CDM cosmologies, in a few CPU seconds.

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arXiv2019

Perturbation theory challenge for cosmological parameters estimation: Matter power spectrum in real space

We study the accuracy with which cosmological parameters can be determined from real space power spectrum of matter density contrast at weakly nonlinear scales using analytical approaches. From power spectra measured in $N$-body simulations and using Markov chain Monte-Carlo technique, the best-fitting cosmological input parameters are determined with several analytical methods as a theoretical template, such as the standard perturbation theory, the regularized perturbation theory, and the effective field theory. We show that at redshift 1, all two-loop level calculations can fit the measured power spectrum down to scales $k \sim 0.2 \, h \, \mathrm{Mpc}^{-1}$ and cosmological parameters are successfully estimated in an unbiased way. Introducing the Figure of bias (FoB) and Figure of merit (FoM) parameter, we determine the validity range of those models and then evaluate their relative performances. With one free parameter, namely the damping scale, the regularized perturbation theory is found to be able to provide the largest FoM parameter while keeping the FoB in the acceptance range.

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