Multi-probe weak lensing, tSZ and X-ray moments double PNG constraints via nonlinear simulations
New simulations propagate primordial non-Gaussianities into nonlinear observables using weak lensing, tSZ and X-ray fields. Second and third moments from the three probes improve f_NL constraints by a factor of two while self-calibrating baryonic systematics. The public pipeline enables immediate use by upcoming multi-wavelength surveys.
The arXiv paper (2607.06692) introduces a multi-wavelength map-making pipeline that propagates PNG signatures through nonlinear structure formation using consistent baryonic models. Second and third moments extracted from the three fields are combined with explicit foreground correlations, allowing self-calibration of astrophysical nuisance parameters that otherwise limit single-probe analyses.
Prior lensing-only constraints suffered from strong degeneracies between PNG amplitudes and baryonic feedback; the addition of tSZ and X-ray moments supplies independent pressure and density information that lifts these degeneracies. This approach accesses the nonlinear regime where PNG imprints are strongest yet previously inaccessible to analytic forecasts.
Related work in Planck 2018 (A&A 641, A9) and DES-Y3 (arXiv:2105.13549) established the baseline sensitivity of individual probes; the new pipeline demonstrates how cross-correlations recover information lost to marginalization. Public release of the simulation suite enables direct tests by other groups.
Next steps require incorporating higher-order statistics and scale cuts below 10 arcmin to realize the projected gains in upcoming surveys such as CMB-S4 and Euclid.
Anbajagane: Combined lensing+tSZ+X-ray analysis on CMB-S4+Euclid data will reach sigma(f_NL)<3 by 2032
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2607.06692)
- [2]Supporting Source(https://arxiv.org/abs/2105.13549)