paper

Cosmic magnification in beyond-Horndeski gravity

arXiv:2311.04169 · doi:10.1088/1475-7516/2025/11/007

Abstract

Cosmic magnification is able to probe the geometry of large-scale structure on cosmological scales, thereby providing another window for probing theories of the late-time cosmic acceleration. It holds the potential to reveal new information on the nature of dark energy and modified gravity. By using the angular power spectrum, we investigated cosmic magnification beyond weak lensing (incorporating all known relativistic corrections) in beyond-Horndeski gravitywith both constant phenomenology and dynamic phenomenology, respectively. For both phenomenologies our results show that the total relativistic signal surpasses cosmic variance (considering an SKA2-like sky coverage) in the magnification angular power spectrum at low redshifts (), hence cosmic-variance reduction methods like multi-tracer analysis will not be needed for surveys at the given . For the individual relativistic signals, we found that the Doppler magnification signal also surpasses cosmic variance and remains the dominant signal, at low , for both phenomenologies. However, the integrated-Sachs-Wolfe, the time-delay, and the gravitational (potential) magnification signals, respectively, are subdominant to both the Doppler magnification signal and cosmic variance, at the same ; hence multi-tracer analysis will be needed to isolate these signals. At high redshifts (), the integrated-Sachs-Wolfe, the time-delay, and the gravitational magnification signals, respectively, appear to surpass cosmic variance and dominate over the Doppler magnification signal for constant phenomenology; whereas for dynamic phenomenology, all these signals diminish significantly and are well below cosmic variance, at all (consistent with recent quintessence analysis). Suggesting that including time-variation in the parameters will be crucial in identifying the true signature of the beyond-Horndeski gravity.

20 pages, 11 figures. v3: New results added, major changes, conclusion modified. Version accepted by JCAP (Abstract above is shortened to comply with arXiv's limit.)

References in corpus (58)