8–12 Jun 2026
Old Prison of Aegina
Europe/Athens timezone

Large-Scale Structure and Primordial Non-Gaussianity with SPHEREx

9 Jun 2026, 12:00
30m
Old Prison of Aegina

Old Prison of Aegina

Aegina island, Greece

Speaker

Henry Grasshorn Gebhardt

Description

SPHEREx is in the process of surveying the full sky every six months in 102 spectro-photometric bands from 0.75 to 5 micrometers. This will allow SPHEREx to measure redshifts for about 500 million galaxies out to about z < 4. The unprecedentedly large volume is forecast to allow measurement of local non-Gaussianity with statistical uncertainty below order unity. For the main part of the talk I will introduce SPHEREx, and it's status after one year of observation. In the second part of the talk I will go into some of the analysis techniques we are developing for SPHEREx, especially the spherical-Fourier-Bessel (SFB) power spectrum that incorporates all wide- and first-order GR effects and does not need an effective redshift approximation, as well as our new in-progress technique to calculate the window convolution matrix, wide-angle effects, and integral constraint for the galaxy power spectrum and bispectrum. I will also highlight some of the systematics challenges associated with the measurement.

Author

Presentation materials