Investigating the imprint of quintessence in cosmic magnification

TL;DR

This paper explores how cosmic magnification, including relativistic effects, can be used to probe dark energy models like quintessence, highlighting the potential and limitations of different signals across redshifts.

Contribution

It analyzes the total relativistic cosmic magnification power spectrum for distinguishing quintessence models, emphasizing the importance of relativistic corrections and redshift dependence.

Findings

Relativistic corrections enable model differentiation at certain redshifts.

Cosmic variance limits detectability of some signals at high redshifts.

Total magnification spectrum approximates lensing at high redshifts.

Abstract

We study cosmic magnification beyond lensing in a late-time universe dominated by quintessence and cold dark matter. The cosmic magnification angular power spectrum, especially going beyond the well-known lensing effect, provides an independent avenue for investigating the properties of quintessence, and hence, dark energy. By analysing the magnification power spectrum at different redshifts, it is possible to extract new information about the large-scale imprint of dark energy, including whether we are able to disentangle different models from one another. Using three well-known quintessence models, we analyse the cosmic magnification angular power spectrum while taking relativistic corrections into account. We found that it will be difficult to distinguish between quintessence models, and quintessence from the cosmological constant, in lensing magnification angular power spectrum on large scales, at redshifts $z \,{\leq}\, 1$; whereas, when relativistic corrections are incorporated, the total magnification angular power spectrum holds the potential to distinguish between the models, at the given $z$. At $z \,{\geq}\, 3$, the lensing magnification angular power spectrum can be a reasonable approximation of the total magnification angular power spectrum. We also found that both the total relativistic and the Doppler magnification signals, respectively, surpass cosmic variance at $z \,{\leq}\, 0.5$: hence the effect may be detectable at the given $z$. On the other hand, the ISW and the time-delay magnification signals, respectively, are surpassed by cosmic variance on all scales, at epochs up to $z \,{=}\, 4.5$, with the gravitational-potential magnification signal being zero.