Constraining Warm Dark Matter With Cosmic Shear Power Spectra

We examine potential constraints from cosmic shear on the dark matter particle mass, assuming all dark matter is made up of light thermal relic particles. Given the theoretical uncertainties concerned in making cosmological predictions in such heat dark matter eventualities we use analytical fits to linear heat dark matter Wood Ranger Power Shears shop spectra and compare (i) the halo model using a mass perform evaluated from these linear energy spectra and Wood Ranger Power Shears shop (ii) an analytical match to the non-linear evolution of the linear energy spectra. We optimistically ignore the competing effect of baryons for this work. We discover approach (ii) to be conservative compared to strategy (i). We consider cosmological constraints using these methods, Wood Ranger Power Shears features buy Wood Ranger Power Shears Power Shears specs marginalising over 4 other cosmological parameters. Using the extra conservative method we find that a Euclid-like weak lensing survey together with constraints from the Planck cosmic microwave background mission primary anisotropies may achieve a lower limit on the particle mass of 2.5 keV.



In the second half of the 20th century, two competing theories for the growth of cosmological structure have been proposed. Within the chilly dark matter (CDM) paradigm (Peebles (1982); Blumenthal et al. 1984); Peebles (1984); Davis et al. In these virialised darkish matter buildings the baryons condense and form luminous objects within the Universe. In the new dark matter (HDM) paradigm (Zel’Dovich (1970); Bond et al. 1980); Bond and Szalay (1983); Centrella et al. Universe, erasing all structure on small scales. In these models, Wood Ranger Power Shears order now Wood Ranger Power Shears review Power Shears the most large structures kind first, producing "Zeldovich pancakes", that later produce smaller objects by fragmentation in a prime-down manner. An example of such a particularly energetic darkish matter particle is a massive energetic neutrino. By the top of the twentieth century it was clear that the hot darkish matter paradigm can't describe the measurements of the cosmic microwave background and the clustering of galaxies and that construction formation in the Universe is, a minimum of overall, hierarchical (Komatsu et al.



2010); Cole et al. 2005); Tegmark et al. 2004); Seljak et al. LambdaCDM paradigm. For instance, it has lengthy been identified that CDM theory predicts many extra small mass haloes than the number of dwarf galaxies that we see across the Milky Way (Diemand et al. Similarly, cuspy galactic cores indicated in some observations are inconsistent with predictions of the CDM (Moore (1994); Simon et al. Moreover, the angular momenta of darkish matter haloes are significantly decrease than those noticed in spiral galaxies (Sommer-Larsen and Wood Ranger Power Shears shop Dolgov (2001); Chen and Jing (2002); Zavala et al. There can also be some discrepancy between the distribution of sizes of mini-voids within the native Universe and CDM predictions (Tikhonov et al. These discrepancies may be resolved by accounting for sure astrophysical processes. Supernova suggestions can extinguish star formation and additional baryonic effects may also affect the properties of the darkish matter density distribution in centres of haloes. However, a suppression of the primordial matter power spectrum on small scales is a beautiful various.



That is most simply achieved by giving dark matter some small preliminary velocity dispersion: not enough to break the very profitable hierarchical structure formation, however enough to make a difference on small scales. Such fashions go underneath the name of heat dark matter (WDM) (Bode et al. 2001); Avila-Reese et al. In warm dark matter fashions, darkish matter particles free-streamed for a short interval in the early Universe, before becoming non-relativistic. This suppression is the principle observational smoking gun of WDM models. Several microscopic fashions for warm dark matter have been proposed. The most common models contain sterile neutrinos (Dodelson and Widrow (1994); Fuller et al. 2003); Asaka et al. 2005); Abazajian (2006); Boyarsky et al. Petraki and Kusenko (2008); Laine and Shaposhnikov (2008); Kusenko (2009); Hamann et al. Bond et al. (1982); Borgani et al. 1996); Fujii and Yanagida (2002); Cembranos et al. 2005); Steffen (2006); Takahashi (2008)) as dark matter particles.