Search for dissertations about: "NATURAL SCIENCES Physics Astronomy and astrophysics Cosmology"
Showing result 11 - 15 of 136 swedish dissertations containing the words NATURAL SCIENCES Physics Astronomy and astrophysics Cosmology.
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11. Radio waves in the ionosphere : Propagation, generation and detection
Abstract : We discuss various topics concerning the propagation, generation, and detec-tionof high-frequency (HF) radio waves in the Earth's ionosphere. With re-gardsto propagation, we derive a full wave Hamiltonian and a polarization evo-lutionequation for electromagnetic waves in a cold, stratified magnetoplasma. READ MORE
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12. Arithmetic and Hyperbolic Structures in String Theory
Abstract : This thesis consists of an introductory text followed by two separate parts which may be read independently of each other. In Part I we analyze certain hyperbolic structures arising when studying gravity in the vicinity of spacelike singularities (the BKL-limit). READ MORE
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13. On the Winds of Carbon Stars and the Origin of Carbon : A Theoretical Study
Abstract : Carbon is the basis for life, as we know it, but its origin is still largely unclear. Carbon-rich Asymptotic Giant Branch (AGB) stars (carbon stars) play an important rôle in the cosmic matter cycle and may contribute most of the carbon in the Galaxy. READ MORE
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14. A Stacked Prism Lens Concept for Next-Generation Hard X-Ray Telescopes
Abstract : Over the past half century, the focusing X-ray telescope has played a very prominent role in X-ray astronomy at the frontier of fundamental physics. The finer angular resolution and increased effective area have enabled more and more exciting discoveries and detailed studies of the high-energy universe, including the cosmic X-ray background (CXB) radiation, black holes in active galactic nuclei (AGN), galaxy clusters, supernova remnants, and so on. READ MORE
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15. Cosmoparticle Physics and String Theory
Abstract : This thesis deals with phenomenological and theoretical aspects of cosmoparticle physics and string theory. There are many open questions in these topics. In connection with cosmology we would like to understand the detailed properties of dark matter, dark energy, generation of primordial perturbations, etc. READ MORE