Warmth elevating the depths: shallower voids with warm dark matter

Lin F. Yang, Mark C. Neyrinck, Miguel A. Aragon-Calvo, Bridget Falck, Joseph Silk

Research output: Contribution to journalArticlepeer-review

177 Downloads (Pure)


Warm dark matter (WDM) has been proposed as an alternative to cold dark matter (CDM), to resolve issues such as the apparent lack of satellites around the Milky Way. Even if WDM is not the answer to observational issues, it is essential to constrain the nature of the dark matter. The effect of WDM on haloes has been extensively studied, but the small-scale initial smoothing in WDM also affects the present-day cosmic web and voids. It suppresses the cosmic "sub-web" inside voids, and the formation of both void haloes and subvoids. In $N$-body simulations run with different assumed WDM masses, we identify voids with the ZOBOV algorithm, and cosmic-web components with the ORIGAMI algorithm. As dark-matter warmth increases (i.e., particle mass decreases), void density minima grow shallower, while void edges change little. Also, the number of subvoids decreases. The density field in voids is particularly insensitive to baryonic physics, so if void density profiles and minima could be measured observationally, they would offer a valuable probe of the nature of dark matter. Furthermore, filaments and walls become cleaner, as the substructures in between have been smoothed out; this leads to a clear, mid-range peak in the density PDF.
Original languageEnglish
Pages (from-to)3606-3614
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
Early online date29 Jun 2015
Publication statusPublished - 21 Aug 2015


  • astro-ph.CO
  • cosmology: theory
  • dark matter
  • RCUK
  • STFC


Dive into the research topics of 'Warmth elevating the depths: shallower voids with warm dark matter'. Together they form a unique fingerprint.

Cite this