Constraining Warm Dark Matter With Cosmic Shear Power Spectra

De Transcription | Bibliothèque patrimoniale numérique Mines ParisTech
Révision datée du 16 novembre 2025 à 15:39 par Kirk69940480 (discussion | contributions)
(diff) ← Version précédente | Voir la version actuelle (diff) | Version suivante → (diff)
Aller à : navigation, rechercher


We investigate potential constraints from cosmic shear on the darkish matter particle mass, assuming all darkish matter is made up of light thermal relic particles. Given the theoretical uncertainties concerned in making cosmological predictions in such heat dark matter situations we use analytical matches to linear warm darkish matter Wood Ranger Power Shears website spectra and examine (i) the halo model using a mass operate evaluated from these linear energy spectra and (ii) an analytical match to the non-linear evolution of the linear energy spectra. We optimistically ignore the competing effect of baryons for brushless motor shears this work. We find approach (ii) to be conservative in comparison with approach (i). We consider cosmological constraints utilizing these strategies, marginalising over 4 different cosmological parameters. Using the extra conservative technique 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 twentieth century, two competing theories for the growth of cosmological construction have been proposed. In the cold darkish matter (CDM) paradigm (Peebles (1982); Blumenthal et al. 1984); Peebles (1984); Davis et al. In these virialised dark matter constructions the baryons condense and kind luminous objects in the Universe. In the recent darkish 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 fashions, the most huge buildings form first, brushless motor shears producing "Zeldovich pancakes", that later produce smaller objects by fragmentation in a top-down manner. An example of such an extremely energetic dark matter particle is a large lively neutrino. By the end 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 structure formation within the Universe is, at the least general, 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 concept predicts many extra small mass haloes than the variety 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 dark matter haloes are considerably lower than those noticed in spiral galaxies (Sommer-Larsen and brushless motor shears Dolgov (2001); Chen and Jing (2002); Zavala et al. There is also some discrepancy between the distribution of sizes of mini-voids within the local Universe and CDM predictions (Tikhonov et al. These discrepancies is likely to be resolved by accounting for sure astrophysical processes. Supernova feedback can extinguish star formation and further baryonic results can also affect the properties of the darkish matter density distribution in centres of haloes. However, garden cordless power shears Wood Ranger Power Shears manual a suppression of the primordial matter Wood Ranger Power Shears warranty spectrum on small scales is an attractive various.



This is most easily achieved by giving dark matter some small preliminary velocity dispersion: not sufficient to interrupt the very profitable hierarchical construction formation, orchard maintenance tool but sufficient to make a difference on small scales. Such models go beneath the title of warm darkish matter (WDM) (Bode et al. 2001); Avila-Reese et al. In heat darkish matter models, darkish matter particles free-streamed for a brief period in the early Universe, earlier than becoming non-relativistic. This suppression is the principle observational smoking gun of WDM fashions. Several microscopic models for warm darkish matter have been proposed. The commonest models include sterile neutrinos (Dodelson and brushless motor shears Widrow (1994); Fuller et al. 2003); Asaka et al. 2005); Abazajian (2006); Boyarsky et al. Petraki and Kusenko (2008); Laine and brushless motor shears Shaposhnikov (2008); Kusenko (2009); Hamann et al. Bond et al. (1982); Borgani et al. 1996); Fujii and brushless motor shears Yanagida (2002); Cembranos et al. 2005); Steffen (2006); Takahashi (2008)) as darkish matter particles.