TDCOSMO 2026: A 3% measurement of the Hubble constant from strong lensing and stellar kinematics
Abstract
We present cosmological constraints from 11 strongly lensed quasars with measured time delays (hereafter, the TDCOSMO-2026 sample). In addition to expanding the sample, we improve many aspects of our blind analysis with respect to our 2025 analysis. Among other improvements, spatially resolved kinematics are available for nine systems, including six with JWST-NIRSpec, compared to one in 2025; for three lens models, JWST-NIRCam images now replace HST; axisymmetric dynamical modeling is applied directly to the spatially resolved data, instead of an axisymmetric correction factor applied to spherical models; and the line-of-sight convergence is now based on the Euclid Flagship simulations instead of the Millennium Simulation. Our baseline and primary result is based on the TDCOSMO-2026 sample, in combination with a prior on Ωm from the DES-Dovekie supernova sample. In the flat Λ cold dark matter (ΛCDM) cosmology, we find H0=71.1+2.4−2.3 km.s−1.Mpc−1, a 3.3% uncertainty that accounts for the mass-sheet degeneracy. The SLACS and SL2S samples are in excellent agreement with the TDCOSMO-2026 sample, improving the precision on H0 in flat ΛCDM to 3.0%. Using the DESI-DR2 baryon acoustic oscillations (BAO) likelihood instead of DES-Dovekie yields fully consistent results. We also present constraints in the open ΛCDM, wCDM, w0waCDM, and wϕCDM cosmologies; the TDCOSMO H0 inference is robust and consistent across all of them. The combination of the TDCOSMO+SLACS+SL2S likelihood with those from DESI-DR2 and DES-Dovekie disfavors w=−1 at the $2.3−2.5σ$ level in all three dark energy extensions that we tested. We find, e.g., w0=−0.88+0.04−0.05 in wϕCDM and w0 = −0.85+0.07−0.06 in w0waCDM, while wa = −0.48+0.46−0.44 remains consistent with zero.
Related
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- Measurement of Substructure from the Kinematics of the GD-1 Stellar Stream
- TDCOSMO XXIX: JWST/NIRSpec IFU Spatially Resolved Kinematics of Three Time-delay Lenses
- TDCOSMO XXX: Spatially resolved kinematics of the deflectors in time-delay lens systems B1608+656 and SDSSJ1206+4332 from JWST-NIRSpec observation
- TDCOSMO 2026: new insights on the Hubble tension from strong lensing time delays
BibTeX
@misc{birrer2026tdcosmo,
title = {{TDCOSMO 2026: A 3% measurement of the Hubble constant from strong lensing and stellar kinematics}},
author = {Simon Birrer and Michele Cappellari and Frédéric Courbin and Christopher D Fassnacht and Pierre Fleury and Joshua A Frieman and Aymeric Galan and Xiang-Yu Huang and Daniel P Johnson and Sanjana Khanolkar and Shawn Knabel and Hrvoje Krizic and Martin Millon and Takahiro Morishita and Veronica Motta and Pritom Mozumdar and Eric Paic and Hadrien Paugnat and Allan G Schweinfurth and Anowar J Shajib and William Sheu and Dominique Sluse and Massimo Stiavelli and Sherry H Suyu and Tommaso Treu and Felipe Urcelay and Devon M Williams and Kenneth C Wong},
howpublished = {HAL},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.14781},
eprint = {2610.14781},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05834676v1},
}
RIS
TY - UNPB
TI - TDCOSMO 2026: A 3% measurement of the Hubble constant from strong lensing and stellar kinematics
AU - Simon Birrer
AU - Michele Cappellari
AU - Frédéric Courbin
AU - Christopher D Fassnacht
AU - Pierre Fleury
AU - Joshua A Frieman
AU - Aymeric Galan
AU - Xiang-Yu Huang
AU - Daniel P Johnson
AU - Sanjana Khanolkar
AU - Shawn Knabel
AU - Hrvoje Krizic
AU - Martin Millon
AU - Takahiro Morishita
AU - Veronica Motta
AU - Pritom Mozumdar
AU - Eric Paic
AU - Hadrien Paugnat
AU - Allan G Schweinfurth
AU - Anowar J Shajib
AU - William Sheu
AU - Dominique Sluse
AU - Massimo Stiavelli
AU - Sherry H Suyu
AU - Tommaso Treu
AU - Felipe Urcelay
AU - Devon M Williams
AU - Kenneth C Wong
PY - 2026
DA - 2026/10/22
PB - HAL
DO - 10.48550/arxiv.2610.14781
UR - https://hal.science/hal-05834676v1
AB - We present cosmological constraints from 11 strongly lensed quasars with measured time delays (hereafter, the TDCOSMO-2026 sample). In addition to expanding the sample, we improve many aspects of our blind analysis with respect to our 2025 analysis. Among other improvements, spatially resolved kinematics are available for nine systems, including six with JWST-NIRSpec, compared to one in 2025; for three lens models, JWST-NIRCam images now replace HST; axisymmetric dynamical modeling is applied directly to the spatially resolved data, instead of an axisymmetric correction factor applied to spherical models; and the line-of-sight convergence is now based on the Euclid Flagship simulations instead of the Millennium Simulation. Our baseline and primary result is based on the TDCOSMO-2026 sample, in combination with a prior on Ω_m from the DES-Dovekie supernova sample. In the flat Λ cold dark matter (ΛCDM) cosmology, we find H_0=71.1^+2.4_−2.3 km.s^−1.Mpc^−1, a 3.3% uncertainty that accounts for the mass-sheet degeneracy. The SLACS and SL2S samples are in excellent agreement with the TDCOSMO-2026 sample, improving the precision on H_0 in flat ΛCDM to 3.0%. Using the DESI-DR2 baryon acoustic oscillations (BAO) likelihood instead of DES-Dovekie yields fully consistent results. We also present constraints in the open ΛCDM, wCDM, w_0w_aCDM, and w_ϕCDM cosmologies; the TDCOSMO H_0 inference is robust and consistent across all of them. The combination of the TDCOSMO+SLACS+SL2S likelihood with those from DESI-DR2 and DES-Dovekie disfavors w=−1 at the $2.3−2.5σ$ level in all three dark energy extensions that we tested. We find, e.g., w_0=−0.88^+0.04_−0.05 in w_ϕCDM and w_0 = −0.85^+0.07_−0.06 in w_0w_aCDM, while w_a = −0.48^+0.46_−0.44 remains consistent with zero.
ER -