American Physical Society | Physics Viewpoint | 2019 May 01
The Dark Energy Survey has combined its analysis of four cosmological observables to constrain the properties of dark energy—paving the way for cosmological surveys that will run in the next decade.
One of the top goals in cosmology today is understanding the dark energy that is responsible for the accelerated expansion of the Universe. Is the dark energy consistent with the cosmological constant of general relativity—representing a constant energy density filling space homogenously? Or can we find deviations from general relativity on cosmological scales that suggest a more complex nature for gravity? Questions like these motivate the current and next generations of surveys that aim to map out ever larger volumes of the Universe, using a wide variety of probes to constrain the properties of dark energy. The Dark Energy Survey (DES) has now derived such constraints from the combined analysis of four canonical observables related to dark energy: supernovae, baryon acoustic oscillations, gravitational lensing, and galaxy clustering. The resulting bounds confirm what we knew from previous studies, which focused on single probes. But the results indicate that this multiprobe approach could allow surveys in the 2020s to improve such constraints by orders of magnitude, possibly bringing us close to solving the dark energy puzzle. ...
- Area of the sky observed by the Dark Energy Survey in its 5-year mission. The different colors indicate different observation runs. SV: preliminary science verification run; Y1: year 1; Y2: year 2; SN fields: areas containing the supernovae used as standard candles to monitor the Universe’s expansion.
Cosmological Constraints from Multiple Probes in the Dark Energy Survey ~ DES Collaboration: T. M. C. Abbott et al