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
2005 ◽  
Vol 143 ◽  
pp. 571
Author(s):  
Eric Switzer ◽  
Kev Abazajian ◽  
Scott Dodelson ◽  
Salman Habib ◽  
Katrin Heitmann

2016 ◽  
Vol 31 (21) ◽  
pp. 1640008 ◽  
Author(s):  
Hans Böhringer ◽  
Gayoung Chon

The high precision measurements of the cosmic microwave background by the Planck survey yielded tight constraints on cosmological parameters and the statistics of the density fluctuations at the time of recombination. This provides the means for a critical study of structure formation in the Universe by comparing the microwave background results with present epoch measurements of the cosmic large-scale structure. It can reveal subtle effects such as how different forms of Dark Matter may modify structure growth. Currently most interesting is the damping effect of structure growth by massive neutrinos. Different observations of low redshift matter density fluctuations provided evidence for a signature of massive neutrinos. Here we discuss the study of the cosmic large-scale structure with a complete sample of nearby, X-ray luminous clusters from our REFLEX cluster survey. From the observed X-ray luminosity function and its reproduction for different cosmological models, we obtain tight constraints on the cosmological parameters describing the matter density, [Formula: see text], and the density fluctuation amplitude, [Formula: see text]. A comparison of these constraints with the Planck results shows a discrepancy in the framework of a pure [Formula: see text]CDM model, but the results can be reconciled, if we allow for a neutrino mass in the range of 0.17 eV to 0.7 eV. Also some others, but not all of the observations of the nearby large-scale structure provide evidence or trends for signatures of massive neutrinos. With further improvement in the systematics and future survey projects, these indications will develop into a definitive measurement of neutrino masses.


2014 ◽  
Vol 89 (10) ◽  
Author(s):  
Amol Upadhye ◽  
Rahul Biswas ◽  
Adrian Pope ◽  
Katrin Heitmann ◽  
Salman Habib ◽  
...  

2011 ◽  
Vol 418 (1) ◽  
pp. 346-356 ◽  
Author(s):  
Federico Marulli ◽  
Carmelita Carbone ◽  
Matteo Viel ◽  
Lauro Moscardini ◽  
Andrea Cimatti

2014 ◽  
Vol 11 (S308) ◽  
pp. 121-124
Author(s):  
Hélène Dupuy

AbstractThere is now no doubt that neutrinos are massive particles fully involved in the non-linear growth of the large-scale structure of the universe. A problem is that they are particularly difficult to include in cosmological models because the equations describing their behavior in the non-linear regime are cumbersome and difficult to handle. In this manuscript I present a new method allowing to deal with massive neutrinos in a very simple way, based on basic conservation laws. This method is still valid in the non-linear regime. The key idea is to describe neutrinos as a collection of single-flow fluids instead of seeing them as a single hot multi-flow fluid. In this framework, the time evolution of neutrinos is encoded in fluid equations describing macroscopic fields, just as what is done for cold dark matter. Although valid up to shell-crossing only, this approach is a further step towards a fully non-linear treatment of the dynamical evolution of neutrinos in the framework of large-scale structure growth.


1991 ◽  
Vol 67 (9) ◽  
pp. 1057-1061 ◽  
Author(s):  
Tanmay Vachaspati ◽  
Alexander Vilenkin

1990 ◽  
Vol 05 (09) ◽  
pp. 1633-1651 ◽  
Author(s):  
ROBERT H. BRANDENBERGER ◽  
LEANDROS PERIVOLAROPOULOS ◽  
ALBERT STEBBINS

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.


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