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arXiv · 2512.14625

kSZ for everyone: the pseudo-Cl approach to stacking

Lea Harscouet·Kevin Wolz·Amy Wayland·David Alonso·Boryana Hadzhiyska
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Abstract

We present a harmonic-space estimator for the cross-correlation between the kinematic Sunyaev-Zel'dovich effect and the reconstructed galaxy momentum field that offers several practical advantages over the traditional stacking approach. The estimator is easy to deploy using relatively modest computational resources and recovers all information available in the galaxy-kSZ cross-correlation. In particular, by using well-understood power spectrum estimation techniques, its statistical uncertainties, including potential correlated uncertainties with other large-scale structure observables, can be easily and accurately estimated. Moreover, standard kSZ stacking measurements can be reconstructed exactly from the estimator at a lower computational cost, employing harmonic-space, catalog-level techniques to recover all small-scale information.

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Lea Harscouet, Kevin Wolz, Amy Wayland, David Alonso, Boryana Hadzhiyska. 2025-12-16. kSZ for everyone: the pseudo-Cl approach to stacking. https://arxiv.org/abs/2512.14625

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