Density perturbations in a finite scale factor singularity universe
نویسندگان
چکیده
منابع مشابه
Large scale perturbations in the open universe.
When considering perturbations in an open (Ω0 < 1) universe, cosmologists retain only sub-curvature modes (defined as eigenfunctions of the Laplacian whose eigenvalue is less than −1 in units of the curvature scale, in contrast with the super-curvature modes whose eigenvalue is between −1 and 0). Mathematicians have known for almost half a century that all modes must be included to generate the...
متن کاملEvolution of density perturbations in a flat FRW universe.
Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of ...
متن کاملDensity Perturbations in an Universe Dominated by the Chaplygin Gas
We study the fate of density perturbations in an Universe dominate by the Chaplygin gas, which exhibit negative pressure. We show that it is possible to obtain the value for the density contrast observed in large scale structure of the Universe by fixing a free parameter in the equation of state of this gas. The negative character of pressure must be significant only very recently. PACS number(...
متن کاملDensity Perturbations in the Universe from Massive Vector Fields
I discuss the possibility of using a massive vector field to generate the density perturbation in the Universe. I find that a scale-invariant superhorizon spectrum of vector field perturbations is possible to generate during inflation. The associated curvature perturbation is imprinted onto the Universe following the curvaton scenario. The mechanism does not generate a long-range anisotropy bec...
متن کاملPerturbations in a non-singular bouncing Universe
We complement the low-energy gravi-dilaton effective action of string theory with a non-local, general-covariant dilaton potential, and obtain homogeneous solutions describing a non-singular (bouncing-curvature) cosmology. We then compute, both analytically and numerically, the spectrum of amplified scalar and tensor perturbations, and draw some general lessons on how to extract observable cons...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review D
سال: 2012
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.86.023522