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Massive Primordial Galaxies Found In ‘Halo’ Of Dark Matter（图）
Massive Primordial Galaxies Halo Dark Matter
2017/12/19
Observations of two galaxies made with the National Science Foundation-funded Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope suggest that large galaxies formed faster than scienti...
Primordial Black Holes May Have Helped to Forge Heavy Elements（图）
Primordial Black Holes Forge Heavy Elements
2017/9/4
Astronomers like to say we are the byproducts of stars, stellar furnaces that long ago fused hydrogen and helium into the elements needed for life through the process of stellar nucleosynthesis.As the...
Peering deep into time with one of the world’s newest, most sophisticated telescopes, astronomers have found a galaxy – AzTEC-3 – that gives birth annually to 500 times the number of suns as the Milky...
Unification models with reheating via Primordial Black Holes
Unification models reheating via Primordial Black Holes
2011/10/20
We study the possibility of reheating the universe through the evaporation of Primordial Black Holes created at the end of inflation. This is shown to allow for the unification of inflation and dark m...
Primordial Non-Gaussianity and Extreme-Value Statistics of Galaxy Clusters
Primordial Non-Gaussianity Extreme-Value Statistics Galaxy Clusters
2011/10/20
What is the size of the most massive object one expects to find in a survey of a given volume? In this paper, we present a solution to this problem using Extreme-Value Statistics. We calculate the pro...
Features in the primordial spectrum: new constraints from WMAP7+ACT data and prospects for Planck
Features primordial spectrum constraints WMAP7+ACT data prospects Planck
2011/10/19
We update the constraints on possible features in the primordial inflationary density perturbation spectrum by using the latest data from the WMAP7 and ACT Cosmic Microwave Background experiments. The...
Gravitational instability of the primordial plasma: anisotropic evolution of structure seeds
Gravitational instability primordial plasma: anisotropic evolution
2011/10/10
We study how the presence of a background magnetic field, of intensity compatible with current observation constraints, affects the linear evolution of cosmological density perturbations at scales bel...
Inflation and primordial non-Gaussianities of "generalized Galileons"
Inflation primordial non-Gaussianities
2011/10/9
We set up cosmological perturbation theory and study the cosmological implications of the so-called `generalized Galileon' developed in \cite{Deffayet:2011gz,horndeski}.This is the most general scalar...
Feynman-like Rules for Calculating n-Point Correlators of the Primordial Curvature Perturbation
ing n-Point Correlators Primordial Curvature Perturbation
2011/10/10
A diagrammatic approach to calculate n-point correlators of the primordial curvature perturbation \zeta was developed a few years ago following the spirit of the Feynman rules in Quantum Field Theory....
Quantum Origin of the Primordial Fluctuation Spectrum and its Statistics
Quantum Origin Primordial Fluctuation Spectrum Statistics
2011/10/9
The account of the origin of cosmic structure, as provided by the standard inflationary paradigm, is not fully satisfactory, as has been argued in Perez et al 2006. The central point of that work is t...
Quantum fluctuations in planar domain-wall space-times: A possible origin of primordial preferred direction
Quantum fluctuations planar domain-wall space-times possible origin primordial preferred direction
2011/10/18
We study the gravitational effects of a planar domain wall on quantum fluctuations of a massless scalar field during inflation. By obtaining an exact solution of the scalar field equation in de Sitter...
Primordial black hole formation and hybrid inflation
Primordial formation hybrid inflation
2011/9/29
We calculate the contribution to the curvature perturbation, that is generated while the waterfall field grows exponentially (which can occur only if the waterfall field mass is $m\gg H$). We consider...
A weak lensing view on primordial non-Gaussianities
cosmology: large-scale structure gravitational lensing methods: analytical
2011/9/29
We investigate the signature of primordial non-Gaussianities in the weak lensing bispectrum, in particular the signals generated by local, orthogonal and equilateral non-Gaussianities. The questions w...
Dark matter from primordial metric fields and the term (grad g_{00})^2
Dark matter primordial metric fields
2011/9/27
It is a well-known truism, inspired on the general theory of relativity, that gravity gravitates. Here we suggest the possibility that dark matter may be caused by the gravitation of the metric. At fi...
Measuring primordial non-Gaussianity through weak lensing peak counts
Measuring primordial non-Gaussianity weak lensing peak counts
2011/1/11
We explore the possibility of detecting primordial non-Gaussianity of the local type using weak lensing peak counts. We measure the peak abundance in sets of simulated weak lensing maps corresponding ...