Cosmology with Voids from the Nancy Grace Roman Space Telescope

November 2025 • 2025ApJ...993..227V

Authors • Verza, Giovanni • Degni, Giulia • Pisani, Alice • Hamaus, Nico • Massara, Elena • Benson, Andrew • Escoffier, Stéphanie • Wang, Yun • Zhai, Zhongxu • Doré, Olivier

Abstract • We provide an accurate forecast of the expected constraining power from the main void statistics—the void size function and the void-galaxy cross-correlation function—to be measured by the Roman reference High Latitude Spectroscopic Survey from the Nancy Grace Roman Space Telescope. Relying on a realistic galaxy mock lightcone, covering 2000 square degrees, we find more than 8 × 10⁴ voids and explore their constraining power in the framework of three different cosmological models: ΛCDM, wCDM, and w₀w_aCDM. This work confirms the strong complementarity of different void statistics and showcases the constraining power to be expected from Roman voids thanks to the combination of its high tracer density and large observed volume.

Links

• PDF https://iopscience.iop.org/article/10.3847/1538-4357/ae07d9/pdf
• PREPRINT http://arxiv.org/abs/2410.19713
• ELECTR https://doi.org/10.3847/1538-4357/ae07d9