Joint Analysis of Small-scale Galaxy Clustering and Galaxy–Galaxy Lensing from BOSS Galaxies

Journal Article · Mon Feb 16 00:00:00 EST 2026 · The Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/ae3bd7· OSTI ID:3018442

Gao, Wenhao ^[1]; Liu, Zhenjie ^[1]; Zhai, Zhongxu ^[2]; Tinker, Jeremy L. ^[3]; Zhang, Jun ^[1]; Banerjee, Arka ^[4]; DeRose, Joseph ^[5]; Guo, Hong ^[6]; Mao, Yao-Yuan ^[7]; Storey-Fisher, Kate ^[8]; Wechsler, Risa H. ^[9]

---

1. Shanghai Jiao Tong University (China)
2. Shanghai Jiao Tong University (China); University of Waterloo, ON (Canada)
3. New York University (NYU), NY (United States)
4. Indian Institute of Science Education and Research (IISER), Pune (India); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
5. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); University of California, Berkeley, CA (United States)
6. Chinese Academy of Sciences (CAS), Shanghai (China). Shanghai Astronomical Observatory (SHAO)
7. University of Utah, Salt Lake City, UT (United States)
8. Stanford University, CA (United States). Kavli Institute for Particle Astrophysics & Cosmology
9. Stanford University, CA (United States). Kavli Institute for Particle Astrophysics & Cosmology; SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

We present a joint analysis of galaxy clustering and galaxy–galaxy lensing measurements from BOSS galaxies using a simulation-based emulation method combined with a halo occupation distribution model. Our emulators are constructed with the Aemulus ν simulations, a suite of wνCDM N-body simulations with massive neutrinos as independent particle species. We combine small-scale analysis of clustering from 0.1 to 60.2 h⁻¹ Mpc and lensing from 1.7 to 60.2 h⁻¹ Mpc to perform cosmological constraints. We split the BOSS galaxies into three redshift bins to measure their clustering and employ galaxies from Dark Energy Camera Legacy Survey and Hyper Suprime-Cam as source galaxies to measure lensing separately. We find that the addition of lensing significantly improves the constraining power on $$S_8 = σ_8(Ω_m/0.3)^{0.5}$$, with a weak improvement for fσ₈. Our results of fσ₈ indicate tensions of around 1σ−4σ below the results of the cosmic microwave background observations of Planck. For S₈, our results are also lower than Planck, and the tension can be mitigated when considering possible systematics in lensing measurement. As a by-product, our analysis prefers a nonzero neutrino mass but without strong significance, with the constraining power dominated by the clustering. Given the accuracy and precision of our model and the observational data, it is anticipated that larger and higher-quality spectroscopic data sets will improve the constraints on this fundamental property in the near future.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: 89243024CSC000002
• OSTI ID: 3018442
• Report Number(s): FERMILAB-PUB--26-0088-V; oai:inspirehep.net:3109456; arXiv:2601.12976
• Journal Information: The Astrophysical Journal, Journal Name: The Astrophysical Journal Journal Issue: 2 Vol. 998; ISSN 0004-637X; ISSN 1538-4357
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English