Resurrecting hot dark matter - Large-scale structure from cosmic strings and massive neutrinos

1988 ◽  
Vol 100 ◽  
pp. 1364
Author(s):  
Robert J. Scherrer
Keyword(s):  
Dark Matter ◽  
Large Scale ◽  
Cosmic Strings ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Massive Neutrinos

COSMIC STRINGS, HOT DARK MATTER AND THE LARGE-SCALE STRUCTURE OF THE UNIVERSE

1990 ◽  
Vol 05 (09) ◽  
pp. 1633-1651 ◽  
Author(s):  
ROBERT H. BRANDENBERGER ◽  
LEANDROS PERIVOLAROPOULOS ◽  
ALBERT STEBBINS
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Large Scale ◽  
Cosmic Strings ◽  
Unit Length ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Rotation Curves ◽  
The Universe

A review of recent results on large-scale structure and galaxy formation in a model with hot dark matter and cosmic strings is given. With cosmic strings seeding perturbations, many of the arguments against hot dark matter disappear. It is shown that spherical accretion about loops leads to dark matter haloes with flat velocity rotation curves. Velocity perturbations due to wakes behind long, moving strings lead to a network of planar overdensities with a distinguished scale of slightly less than 40×40 Mpc2. If the mass per unit length μ exceeds a certain bound, then the wakes become nonlinear by the present time. In this case, their thickness can be calculated.

scholarly journals Summary

1988 ◽  
Vol 130 ◽  
pp. 495-505
Author(s):  
P. J. E. Peebles
Keyword(s):  
Dark Matter ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Cosmic Strings ◽  
Large Scale Structure ◽  
Observational Evidence ◽  
Scale Structure ◽  
Scale Invariant ◽  
The Real ◽  
Weak Points

This conference has been marked by our willingness to entertain grand schemes of synthesis of theoretical ideas and the observational evidence on how galaxies and large-scale structure might have formed. At IAU Symposium 104 on this subject held in Crete just 5 years ago there was little discussion of how all the pieces of the puzzle might fit together. Now we have at least three candidate grand syntheses that have been worked out in some detail and have been discussed here: scale-invariant cold dark matter, by Frenk; massive cosmic strings, by Turok; and exploding magnetized superconducting cosmic strings, by Ostriker. I have accordingly placed each of the topics I want to review under the heading of the grand scheme for which it seems most embarrassing. This negative approach is a little unfair, but I think we can take it as given that we would not be considering a scheme that did not have many good points, and that the real interest is the probing of weak points by which we hope to learn which schemes might be strengthened, which might safely be abandoned.

Formation of Large-Scale Structure from Cosmic Strings and Massive Neutrinos

1989 ◽  
Vol 62 (4) ◽  
pp. 379-382 ◽  
Author(s):  
Robert J. Scherrer ◽  
Adrian L. Melott ◽  
Edmund Bertschinger
Keyword(s):  
Large Scale ◽  
Cosmic Strings ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Massive Neutrinos

scholarly journals Large-Scale Structure in the Universe: Spatial Distribution and Peculiar Velocities

1987 ◽  
Vol 124 ◽  
pp. 335-348
Author(s):  
Neta A. Bahcall
Keyword(s):  
Dark Matter ◽  
Spatial Distribution ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Clusters Of Galaxies ◽  
Large Scale Structures ◽  
Peculiar Velocities ◽  
Scale Structures ◽  
The Universe

The evidence for the existence of very large scale structures, ∼ 100h−1Mpc in size, as derived from the spatial distribution of clusters of galaxies is summarized. Detection of a ∼ 2000 kms−1 elongation in the redshift direction in the distribution of the clusters is also described. Possible causes of the effect are peculiar velocities of clusters on scales of 10–100h−1Mpc and geometrical elongation of superclusters. If the effect is entirely due to the peculiar velocities of clusters, then superclusters have masses of order 1016.5M⊙ and may contain a larger amount of dark matter than previously anticipated.

scholarly journals Anti-symmetric clustering signals in the observed power spectrum

2021 ◽  
Vol 2021 (12) ◽  
pp. 003
Author(s):  
José Fonseca ◽  
Chris Clarkson
Keyword(s):  
Dark Matter ◽  
Power Spectrum ◽  
Euler Equation ◽  
Large Scale ◽  
Signal To Noise Ratio ◽  
Power Spectra ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Signal To Noise ◽  
Peculiar Velocities

Abstract In this paper, we study how to directly measure the effect of peculiar velocities in the observed angular power spectra. We do this by constructing a new anti-symmetric estimator of Large Scale Structure using different dark matter tracers. We show that the Doppler term is the major component of our estimator and we show that we can measure it with a signal-to-noise ratio up to ∼ 50 using a futuristic SKAO HI galaxy survey. We demonstrate the utility of this estimator by using it to provide constraints on the Euler equation.

scholarly journals Large-Scale Structure of the Universe in Unstable Dark Matter Models

1988 ◽  
Vol 130 ◽  
pp. 293-300
Author(s):  
A.G. Doroshkevich ◽  
A.A. Klypin ◽  
M.U. Khlopov
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Large Scale ◽  
Numerical Models ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Microwave Background ◽  
Physical Background ◽  
The Mean ◽  
The Universe

Processes of the formation and the evolution of the large-scale structure are discussed in the framework of unstable dark matter models. Six numerical models are presented. The projected distribution of simulated galaxies on the sky, wedge diagrams, correlation functions and the mean linear scale of voids are presented. Physical background of the hypothesis of unstable particles and possible observational tests are discussed. The level of the microwave background fluctuations is estimated analytically. Special attention is given to late stage of supercluster evolution and galaxy formation.

scholarly journals Towards Understanding the Large-Scale Structure?

1987 ◽  
Vol 124 ◽  
pp. 415-432
Author(s):  
Avishai Dekel
Keyword(s):  
Dark Matter ◽  
First Principles ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Ad Hoc ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Observational Constraints ◽  
Microwave Background ◽  
Satisfactory Theory

Although some theories, such as that of cold dark matter, are quite successful in explaining certain aspects of the formation of structure, we seem not to approach a satisfactory theory which can easily account for all the observational constraints on all scales. Most difficult to explain are the indicated clustering of clusters and bulk velocities on very large scales, when considered together with the structure on galactic scales and the isotropy of the microwave background. If these observations are correct, the only scenarios that can work are hybrids of certain sorts, which involve somewhat ad hoc choices of parameters; they are not the theories that would have emerged naturally from first principles, and they do not satisfy the criteria of simplicity and elegancy. I will discuss the currently popular scenarios and the apparent difficulties they face.

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