http://arxiv.org/abs/2004.11643
High-precision cosmological probes have revealed a small but significant tension between the parameters measured with different techniques, one of which is based on time delays in gravitational lenses. We discuss a new way of using time delays for cosmology, taking advantage of the extreme precision expected for lensed Fast Radio Bursts, short flashes of radio emission originating at cosmological distances. With coherent methods the achievable precision is sufficient to even measure how time delays change over the months and years, which can also be interpreted as differential redshifts between the images. It turns out that uncertainties arising from the unknown mass distribution of gravitational lenses can be eliminated by combining time delays with their time derivatives. Other effects, most importantly relative proper motion, can be measured accurately and separated from the cosmological effects. With a mock sample of simulated lenses we show that strong constraints on cosmological parameters are potentially possible. Finally the lensed images can be used as galactic interferometer to resolve structures and motions of the burst sources with insanely high resolution and help revealing their currently unknown physical nature.
O. Wucknitz, L. Spitler and U. Pen
Mon, 27 Apr 20
32/45
Comments: Submitted to A&A, 14 pages