The Structure of the Universe on 100 Mpc Scales
نویسنده
چکیده
Observational evidence for the presence of a preferred scale around 100 Mpc in the distribution of high-density regions in the Universe is summarised. Toy models with various degrees of regularity are analysed to understand better the observational data. Predictions of models which produce a feature on the initial power spectrum of matter are analysed and compared with new observational data on the CMB angular spectrum, cluster mass function, and galaxy and cluster power spectrum.
منابع مشابه
The Universe on Very Large Scales: A View from the Las Campanas Redshift Survey
The Las Campanas Redshift Survey (LCRS) is among the first galaxy redshift surveys to sample a reasonably fair volume of the local Universe. On the largest scales (≫ 100 h Mpc), the galaxy distribution appears smooth; on relatively small scales ( < ∼ 10 h Mpc), the LCRS tends to confirm the clustering characteristics observed in previous, shallower surveys. Here, however, we concern ourselves p...
متن کاملThe Large Scale Structure of the Universe: Theory vs. Observations *
Observations indicate that the Universe is homogeneous and isotropic on scales ≥ 100 200 Mpc., whereas on smaller scales, its fundamental units – galaxies – cluster together to form groups, clusters and even superclusters, with effective mass scales ranging from 10M⊙ (groups) to 10 M⊙ (superclusters). There are also indications that most of the Universe consists of large empty regions – voids, ...
متن کاملLarge Scale Structure of the Universe: Current Problems
According to current paradigms the Universe is homogeneous and isotropic on large scales, density perturbations grow from small random fluctuations generated in the early stage of the evolution (inflation), and the dynamics of the Universe is dominated by cold dark matter (CDM) with some possible mixture of hot dark matter (HDM). On small scales galaxies are associated in groups and clusters. U...
متن کاملA New Measure of the Clustering of QSO Heavy–Element Absorption–Line Systems
We examine the line–of–sight clustering of QSO heavy–element absorption–line systems, using a new measure of clustering, called the reduced second moment measure, K(r), that directly measures the mean over–density of absorbers on scales ∼< r. This measure — while closely related to other second–order measures such as the correlation function or the power spectrum — has a number of distinct stat...
متن کاملThe 2 D Power Spectrum of the Las Campanas Redshift Survey : Detection of Excess Power on 100 h � 1 Mpc
We have measured the 2 dimensional (2D) power spectrum of the Las Campanas Redshift Survey on scales between 30 and 200 h ?1 Mpc (q 0 = 0:5, H o = 100h km sec ?1 Mpc ?1). Such an analysis is more sensitive to structure on scales > 50 h ?1 Mpc than a full 3 dimensional analysis given the geometry of the survey. We nd a strong peak in the power spectrum at 100 h ?1 Mpc relative to the smooth cont...
متن کامل