Detectability of weak lensing modifications under Galileon theories

作者：Park Youngsoo^*; Wyman Mark

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2015, 91(6): 064012.

DOI：10.1103/PhysRevD.91.064012

Theories of modified gravity attempt to reconcile physics at the largest and the smallest scales by explaining the accelerated expansion of our Universe without introducing the cosmological constant. One class of such theories, known as Galileon theories, predicts lensing potentials of spherically symmetric bodies, such as dark matter halos, to receive a featurelike modification at the 5% level. With the advent of next-generation photometric surveys, such modifications can serve as novel probes of modified gravity. Assuming an Large Synoptic Survey Telescope-like fiducial data set, we produce halo-shear power spectra for cold dark matter and Galileon scenarios and perform a Fisher analysis including cosmological, nuisance, and Galileon parameters to study the detectability of the aforementioned modifications. With the cold dark matter scenario as our null hypothesis, we conclude, with a number of idealized assumptions and approximations, that the detection of Galileon modifications could in principle reach up to 4-sigma if present, or strongly excluded in a nondetection, with a tomography of four redshift bins and four mass bins, an Large Synoptic Survey Telescope-like set of survey parameters, and Planck priors on cosmological parameters.

• 出版日期2015-3-3