scholarly journals Peculiar velocity field in structure formation theories with cosmic strings

1998 ◽  
Vol 57 (8) ◽  
pp. 4663-4668 ◽  
Author(s):  
Carsten van de Bruck
Keyword(s):  
Velocity Field ◽  
Structure Formation ◽  
Cosmic Strings ◽  
Peculiar Velocity

Large-Scale Peculiar Velocity Field Due to Infinitely Long Cosmic Strings

1993 ◽  
Vol 415 ◽  
pp. 445 ◽  
Author(s):  
Tetsuya Hara ◽  
Petri Maehoenen ◽  
Shigeru Miyoshi
Keyword(s):  
Velocity Field ◽  
Large Scale ◽  
Cosmic Strings ◽  
Peculiar Velocity

scholarly journals GENERAL RELATIVISTIC RELATION BETWEEN DENSITY CONTRAST AND PECULIAR VELOCITY

2002 ◽  
Vol 11 (03) ◽  
pp. 321-336 ◽  
Author(s):  
REZA MANSOURI ◽  
SOHRAB RAHVAR
Keyword(s):  
Velocity Field ◽  
Structure Formation ◽  
Light Cone ◽  
Gravitational Force ◽  
Relativistic Effects ◽  
Density Contrast ◽  
Linear Perturbation ◽  
Density Spectrum ◽  
Peculiar Velocity ◽  
General Relativistic

Concepts like peculiar velocity, gravitational force, and power spectrum and their interrelationships are of utmost importance in the theories of structure formation. The observational implementation of these concepts is usually based on the Newtonian hydrodynamic equations, but used up to scales where general relativistic effects come in. Using a perturbation of FRW metric in harmonic gauge, we show that the relativistic effects reduce to light cone effects including the expansion of the universe. Within the Newtonian gravitation, the linear perturbation theory of large scale structure formation predicts the peculiar velocity field to be directly proportional to gravitational force due to the matter distribution. The corresponding relation between peculiar velocity field and density contrast has been given by Peebles. Using the general relativistic perturbation we have developed, this familiar relation is modified by doing the calculation on the light cone in contrast to the usual procedure of taking a spacelike slice defined at a definite time. The velocity and density-spectrum are compared to the familiar Newtonian expressions. In particular, the relativistic β-value obtained is reduced and leads to an increased bias factor or a decreased expected amount of the dark matter in a cluster.

scholarly journals Using cosmic strings to relate local geometry to spatial topology

2017 ◽  
Vol 26 (04) ◽  
pp. 1750033
Author(s):  
Christopher Levi Duston
Keyword(s):  
Structure Formation ◽  
Early Universe ◽  
Cosmic Strings ◽  
Local Geometry ◽  
Observational Constraints ◽  
Observable Universe ◽  
Global Properties ◽  
Global Topology ◽  
Spatial Topology ◽  
Spatial Section

In this paper, we will discuss how cosmic strings can be used to bridge the gap between the local geometry of our spacetime model and the global topology. The primary tool is the theory of foliations and surfaces, and together with observational constraints, we can isolate several possibilities for the topology of the spatial section of the observable universe. This implies that the discovery of cosmic strings would not just be significant for an understanding of structure formation in the early universe, but also for the global properties of the spacetime model.

scholarly journals AN UNBIASED METHOD OF MODELING THE LOCAL PECULIAR VELOCITY FIELD WITH TYPE Ia SUPERNOVAE

2011 ◽  
Vol 732 (2) ◽  
pp. 65 ◽  
Author(s):  
Anja Weyant ◽  
Michael Wood-Vasey ◽  
Larry Wasserman ◽  
Peter Freeman
Keyword(s):  
Velocity Field ◽  
Type Ia Supernovae ◽  
Peculiar Velocity ◽  
Type Ia ◽  
Ia Supernovae

Erratum: “Hierarchical Object Formation in the Peculiar Velocity Field” (ApJ, 634, 20 [2005])

2007 ◽  
Vol 659 (2) ◽  
pp. 1792-1793
Author(s):  
Hideaki Mouri ◽  
Yoshiaki Taniguchi
Keyword(s):  
Velocity Field ◽  
Peculiar Velocity

scholarly journals Kinematical Evolution of the Pairwise Velocity Field of Galaxies

1999 ◽  
Vol 183 ◽  
pp. 265-265
Author(s):  
Naoki Seto ◽  
Jun'ichi Yokoyama
Keyword(s):  
Nonlinear Dynamics ◽  
Velocity Field ◽  
Numerical Simulations ◽  
Exponential Distribution ◽  
Relative Velocity ◽  
Statistical Distribution ◽  
Peculiar Velocity ◽  
Highly Nonlinear ◽  
Velocity Dispersions

It has been a long-standing cosmological issue to explain why the statistical distribution of the radial pairwise peculiar velocity of galaxies has an exponential shape rather than the Gaussian, as suggested by observations and explicitly shown by results of N-body simulations. Previous explanations on the exponential distribution are based on highly nonlinear dynamics of galactic systems (R < 1h–1 Mpc). That is, the exponential feature appears as a result of superposition of Gaussian velocity distributions in clumps with various velocity dispersions. Hence although this model is suitable to account for a symmetric exponential distribution with vanishing mean net relative velocity, a more elaborate treatment is necessary in order to reproduce an asymmetric exponential distribution with its peak at a negative relative velocity as observed in numerical simulations.

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