Doppler peaks from active perturbations
ArXiv astro-ph/9511042 (1995)
Abstract:
We examine how the qualitative structure of the Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy depends on the fundamental nature of the perturbations which produced them. The formalism of Hu and Sugiyama is extended to treat models with cosmic defects. We discuss how perturbations can be ``active'' or ``passive'' and ``incoherent'' or ``coherent'', and show how causality and scale invariance play rather different roles in these various cases. We find that the existence of secondary Doppler peaks and the rough placing of the primary peak unambiguously reflect these basic properties.Causality, randomness, and the microwave background
ArXiv astro-ph/9505030 (1995)
Abstract:
Fluctuations in the cosmic microwave background (CMB) temperature are being studied with ever increasing precision. Two competing types of theories might describe the origins of these fluctuations: ``inflation'' and ``defects''. Here we show how the differences between these two scenarios can give rise to striking signatures in the microwave fluctuations on small scales, assuming a standard recombination history. These should enable high resolution measurements of CMB anisotropies to distinguish between these two broad classes of theories, independent of the precise details of each.COSMIC STRINGS IN AN OPEN UNIVERSE WITH BARYONIC AND NONBARYONIC DARK-MATTER
PHYSICAL REVIEW LETTERS 74:18 (1995) 3522-3525
Cosmic Strings in an Open Universe with Baryonic and Non-Baryonic Dark Matter
ArXiv astro-ph/9410032 (1994)
Abstract:
We study the effects of cosmic strings on structure formation in open universes. We calculate the power spectrum of density perturbations for two class of models: one in which all the dark matter is non baryonic (CDM) and one in which it is all baryonic (BDM). Our results are compared to the 1 in 6 IRAS QDOT power spectrum. The best candidates are then used to estimate $\mu$, the energy per unit length of the string network. Some comments are made on mechanisms by which structures are formed in the two theories.INFLATION AND SQUEEZED QUANTUM STATES
PHYSICAL REVIEW D 50:8 (1994) 4807-4820