Degree Scale Microwave Anisotropies in NonGaussian Theories of Cosmic Structure Formation
نویسندگان
چکیده
Abstract The COBE satellite’s maps of the cosmic microwave background (CMB) anisotropy do not have the resolution to discriminate between theories of cosmic structure formation based on inflation, and those based on field ordering following a symmetry breaking phase transition. For this purpose it is critical to resolve the CMB anisotropy on degree scales. In this paper we report on detailed calculations of the degree scale anisotropies predicted in the global string, monopole, texture and nontopological texture scenarios of structure formation, emphasising their distinct character from those predicted by inflation, and commenting on the prospects of their detection in the near future.
منابع مشابه
The Doppler Peaks from Cosmic Texture
We compute the angular power spectrum of temperature anisotropies on the microwave sky in the cosmic texture theory, with standard recombination assumed. The spectrum shows`Doppler' peaks analogous to those in scenarios based on primordial adiabatic uctuations such as`standard CDM', but at quite diierent angular scales. There appear to be excellent prospects for using this as a discriminant bet...
متن کاملImplications of the Background Radiation for Cosmic Structure Formation
The cosmic microwave background (CMB) is a remarkably distortionless blackbody, and this strongly constrains the amount of energy that can have been injected at high redshift, thereby limiting the role that hydrodynamical amplification can have played in cosmic structure formation. The current data on primary anisotropies (those calculated using linear response theory) provide very strong suppo...
متن کاملCosmological Inflation, Microwave Background Anisotropies and Large Scale Structure of the Universe
Cosmological inflation provides the simplest and most promising mechanism for generating fluctuations for structure formation. Using powerful HamiltonJacobi methods, I will describe (1) how to compute density fluctuations and cosmic microwave anisotropies arising from inflation, and (2) improvements of the Zel’dovich approximation describing gravitational collapse. I compare these results with ...
متن کاملTopological Defect Models of Structure Formation after the Cobe Discovery of Cmb Anisotropies
The COBE satellite has discovered anisotropies in the cosmic microwave background (CMB) consistent with a scale invariant spectrum of density perturbations1). As reviewed in this lecture, topological defect models of structure formation generically produce such a spectrum. We give a summary of the cosmic string and global texture models, focusing on distinct observational signatures in large-sc...
متن کاملFrom microwave anisotropies to cosmology.
Fluctuations in the temperature of the cosmic microwave background have now been detected over a wide range of angular scales, and a consistent picture seems to be emerging. This article describes some of the implications for cosmology. Analysis of all of the published detections suggests the existence of a peak on degree scales with a height 2.4 to 10 (90 percent confidence level) times the am...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008