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arXiv · 2603.23612

Reducing cosmological degeneracies by combining multiple classes of LISA gravitational-wave standard sirens

Danny Laghi·Nicola Tamanini·Alberto Sesana·Jonathan Gair·Enrico Barausse·Chiara Caprini·Walter Del Pozzo·Alberto Mangiagli·Sylvain Marsat
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Abstract

We present the first joint gravitational-wave cosmological inference with LISA extreme mass-ratio inspirals at $z\lesssim1$ (galaxy redshifts) and massive black hole binaries at $z\gtrsim1$ (electromagnetic counterparts). Combining these standard sirens reduces cosmological degeneracies and yields competitive constraints on the Hubble constant $H_0$ and the dark-energy equation-of-state parameter $w_0$. This highlights LISA's potential for late-time cosmology across a broad redshift range with systematics distinct from electromagnetic distance indicators.

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Danny Laghi, Nicola Tamanini, Alberto Sesana, Jonathan Gair, Enrico Barausse, Chiara Caprini, Walter Del Pozzo, Alberto Mangiagli, Sylvain Marsat. 2026-03-24. Reducing cosmological degeneracies by combining multiple classes of LISA gravitational-wave standard sirens. https://arxiv.org/abs/2603.23612

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