On structure formation in the universe

1994 ◽  
Vol 222 (1-2) ◽  
pp. 205-212
Author(s):  
A. Satya Narayanan
Keyword(s):  
Structure Formation ◽  
The Universe

scholarly journals Supercomputer simulations of structure formation in the Universe

2016 ◽  
Vol 12 (S325) ◽  
pp. 10-16
Author(s):  
Tomoaki Ishiyama
Keyword(s):  
Domain Decomposition ◽  
Structure Formation ◽  
Short Range ◽  
Large Scale ◽  
Massively Parallel ◽  
Average Performance ◽  
And Performance ◽  
Performance Results ◽  
The Universe ◽  
Peak Speed

AbstractWe describe the implementation and performance results of our massively parallel MPI†/OpenMP‡ hybrid TreePM code for large-scale cosmological N-body simulations. For domain decomposition, a recursive multi-section algorithm is used and the size of domains are automatically set so that the total calculation time is the same for all processes. We developed a highly-tuned gravity kernel for short-range forces, and a novel communication algorithm for long-range forces. For two trillion particles benchmark simulation, the average performance on the fullsystem of K computer (82,944 nodes, the total number of core is 663,552) is 5.8 Pflops, which corresponds to 55% of the peak speed.

scholarly journals Structure Constraints from Large Angle CMB Anisotropies

1992 ◽  
Vol 9 ◽  
pp. 319-321
Author(s):  
J. Richard Bond
Keyword(s):  
Correlation Function ◽  
Structure Formation ◽  
Large Distance ◽  
Large Angle ◽  
Microwave Background ◽  
Scale Invariant ◽  
Intermediate Angle ◽  
History Of ◽  
Adiabatic Fluctuations ◽  
The Universe

Constraints on models of cosmic structure formation that can be drawn from current limits on large angle microwave background anisotropies are now competitive with those from recent small and intermediate angle experiments and are relatively insensitive to the reheating history of the Universe. Here I give limits on Gaussian scale invariant adiabatic fluctuations and describe the role that the large angle results play in constraining models with enhanced large distance galaxy clustering power inferred from correlation function measurements is described.

scholarly journals AN ALTERNATIVE INTERPRETATION FOR THE MODULI FIELDS OF THE COSMOLOGY ASSOCIATED TO TYPE IIB SUPERGRAVITY WITH FLUXES

2008 ◽  
Vol 23 (13) ◽  
pp. 1949-1962 ◽  
Author(s):  
TONATIUH MATOS ◽  
JOSÉ-RUBÉN LUÉVANO ◽  
HUGO GARCÍA-COMPEÁN ◽  
J. ALBERTO VÁZQUEZ
Keyword(s):  
Structure Formation ◽  
Alternative Interpretation ◽  
Linear Regime ◽  
Superstring Theory ◽  
Supergravity Theory ◽  
Cosmological Observations ◽  
Λcdm Model ◽  
Free Parameters ◽  
Quintessence Field ◽  
The Universe

The aim of this work is to provide a basis to interpret the dilaton as the dark matter of the universe, in the context of a particular cosmological model derived from type IIB supergravity theory with fluxes. In this theory, the dilaton is usually interpreted as a quintessence field. But, with this alternative interpretation we find that (in this supergravity model) the model gives a similar evolution and structure formation of the universe compared with the ΛCDM model in the linear regime of fluctuations of the structure formation. Some free parameters of the theory are fixed using the present cosmological observations. In the nonlinear regime there are some differences between the type IIB supergravity theory with the traditional CDM paradigm. The supergravity theory predicts the formation of galaxies earlier than the CDM and there is no density cusp in the center of galaxies. These differences can distinguish both models and might give a distinctive feature to the phenomenology of the cosmology coming from superstring theory with fluxes.

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