Dark matter is one of the most fascinating open issues in modern physics. So far, evidence of its existence is purely of a gravitational nature, which does not satisfy the question of what it actually is. If dark matter consists of unknown elementary particles or exotic macroscopic bodies, it is expected to produce a signal characteristic to its particle nature. Considering different environments for dark matter searches is pivotal, since each target will have its own advantages and disadvantages. Dwarf spheroidal galaxies, the galactic centre and clusters of galaxies have been thoroughly investigated in the past years, yet no indisputable evidence of a dark matter signal has been confirmed.
In this talk, I will explain why cosmic voids are an interesting new target for dark matter searches. I will show that the expected signal-to-noise ratio resulting from decaying dark matter is significantly more favourable in cosmic voids as compared to dark matter halos, as a result of the reduced astrophysical background. This opens an exciting new avenue for dark matter searches. In particular, I will show that galaxy surveys correlated with future generation gamma-ray detectors will be able to observe a dark matter signal with a high significance, leading to a significant improvement of the bounds on the dark matter lifetime for dark matter masses in the range 25-900 GeV.
