TASTY: Attacking astrophysical systematics of weak gravitational lensing with external probes скачать в хорошем качестве

TASTY: Attacking astrophysical systematics of weak gravitational lensing with external probes

Speaker: Jamie McCullough Abstract: I will informally discuss obstacles to the cosmological analysis of next-generation weak lensing surveys on small scales. These modeling challenges include our uncertain knowledge of galaxy intrinsic alignments (IA) and the suppression of matter power spectrum due to explosive baryon feedback. Both of these modeling challenges are relatively uninformed from lensing alone but can be constrained in combination with external measurements — in the case of IA by spectroscopic measurements of galaxy redshifts, and for baryon feedback by probes of gas from X-ray and CMB observations. We present an analysis of the Dark Energy Survey Year 3 limited to blue, star-forming galaxies that lessen the impact of IA, and that makes use of tailored priors on IA informed by spectroscopic direct measurements (DESI, eBOSS), and informed priors on baryon feedback from external gas probes (kSZ, X-ray, GGL). This robust handling of systematic uncertainty allows us to push to small cosmic scales and significantly improve our cosmological precision, laying foundation for more powerful surveys like Rubin, Euclid, and Roman in the next decade.