November 14, 2024
MIAPbP@ORIGINS
Europe/Berlin timezone

Cosmology with weak lensing peaks and voids

Nov 14, 2024, 11:40 AM
20m
MIAPbP Seminar Room (MIAPbP@ORIGINS)

MIAPbP Seminar Room

MIAPbP@ORIGINS

https://www.munich-iapbp.de/contact
Contributed talk Morning session 2

Speaker

Chris Davies (USM LMU)

Description

Maximising the information that can be extracted from weak lensing measurements is a key goal for LSST and Euclid. This is typically achieved through statistics that are complementary to the cosmic shear two-point correlation function.

In this talk I will present the development of two such complementary statistics.

The first is weak lensing peaks. Typically, only the peak abundance is used to test cosmology. I will show how the clustering of peaks can be used to significantly improve the sensitivity of weak lensing peaks to cosmological parameters.

Secondly, I will present weak lensing voids, a new weak lensing statistic, that corresponds to a new void definition, which also captures a wealth of cosmological information.

I use the cosmoSLICS, FORGE, and BRIDGE simulations to measure the weak lensing peak and void statistics for a range of cosmological and gravitational parameters. The simulation data is used to train a machine learning emulator, which is used to generate parameter constraint forecasts from mock observations.

I will show that both peaks and voids can double our constraining power on cosmological models, relative to the standard shear two-point correlation function.

Finally, I will present ongoing work applying these methods to the DES Y3 data.

Abstract title Cosmology with weak lensing peaks and voids

Author

Chris Davies (USM LMU)

Presentation materials

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