Sökning: "black hole"
Visar resultat 11 - 15 av 50 avhandlingar innehållade orden black hole.
11. Linear response theory: from black holes to Weyl systems and back
Sammanfattning : Linear response theory is a powerful calculation tool in quantum field theory. We apply this framework to a variety of models originating from distinct areas in theoretical physics and for different reasons. LÄS MER
12. A Kerr-full Study of Higher-Spin Amplitudes : An on-shell construction of higher-spin amplitudes for black holes and strings
Sammanfattning : Recently, it was shown that Kerr black holes can be described via the classical infinite-spin limit of a special class of scattering amplitudes in a massive higher-spin quantum field theory. Although this approach has successfully obtained state-of-the-art results for spinning black-hole binaries, only the three-point amplitude that describes Kerr is known in full generality and a full understanding of the underlying Lagrangian is still missing. LÄS MER
13. Nonspherical black holes and spacetime reconstructions
Sammanfattning : This thesis consists of three papers in mathematical general relativity. The first paper concerns inverse problems and reconstruction of spacetimes from boundary data. We consider boundary data in the form of broken geodesics with different causal types, which have the physical interpretation of relativistic fireworks. LÄS MER
14. Symmetries and black holes in Hassan–Rosen bimetric theory
Sammanfattning : The Hassan–Rosen bimetric theory is an extension of general relativity which considers the interaction between two metric fields defined on the same differentiable manifold. Self-accelerating cosmologies are exact solutions of this theory, and this makes it interesting to explore. LÄS MER
15. Attraction and Rejection : On the love–hate relationship between stars and black holes
Sammanfattning : Solitary stars wandering too close to the supermassive black hole at the centre of their galaxy may become tidally disrupted, if the tidal forces due to the black hole overcome the self-gravity holding the star together. Depending on the strength of the encounter, the star may be partially disrupted, resulting in a surviving stellar core and two tidal arms, or may be completely disrupted, resulting in a long and thin tidal stream expected to fall back and circularize into an accretion disc (the two cases are illustrated on the cover of this thesis). LÄS MER
