Sökning: "spacetime"

Visar resultat 6 - 10 av 29 avhandlingar innehållade ordet spacetime.

  1. 6. Nonspherical black holes and spacetime reconstructions

    Författare :Eric Staffas; Mattias Dahl; Jan Metzger; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    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

  3. 7. Dualities, Symmetries and Unbroken Phases in String Theory : Probing the Composite Nature of the String

    Författare :Johan Engquist; Joseph Minahan; Charlotte Kristjansen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Theoretical Physics; String Theory; M-Theory; Higher Spin Gauge Theory; Super Yang-Mills Theory; Anti-de Sitter Spacetime; Singletons; Massless Higher Spin Gauge Fields; AdS CFT Correspondence; Spin Chains; Semiclassical Strings; Tensionless Limits; Conformal Symmetry; Supersymmetry; Higher Spin Gauge Symmetry; Integrability; Fysik; Physics; Fysik;

    Sammanfattning : The thesis treats aspects of string/M-theory in anti-de Sitter spacetimes and their supersymmetric completions. By applying the AdS/CFT correspondence, as well as models of spin chains and singletons, we try to attain a better understanding of the underlying symmetries and the unbroken phases of string/M-theory. LÄS MER

  4. 8. Multipole moments of axisymmetric spacetimes

    Författare :Thomas Bäckdahl; Magnus Herberthson; Brian Edgar; Kjell Rosquist; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; multipole moments; axisymmetry; spacetimes; prescribed; solutions; static; stationary; Kerr; Weyl; Ernst; Theory of relativity; gravitation; Relativitetsteori; gravitation;

    Sammanfattning : In this thesis we study multipole moments of axisymmetric spacetimes. Using the recursive definition of the multipole moments of Geroch and Hansen we develop a method for computing all multipole moments of a stationary axisymmetric spacetime without the use of a recursion. LÄS MER

  5. 9. Symmetries and black holes in Hassan–Rosen bimetric theory

    Författare :Francesco Torsello; Edvard Mörtsell; Mikael von Strauss; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; teoretisk fysik; Theoretical Physics;

    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

  7. 10. Cosmological models, nonideal fluids and viscous forces in general relativity

    Författare :Daniele Gregoris; Kjell Rosquist; Alan Coley; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gravity; exact model; black hole; friction; teoretisk fysik; Theoretical Physics;

    Sammanfattning : This thesis addresses the open questions of providing a cosmological model describing an accelerated expanding Universe without violating the energy conditions or a model that contributes to the physical interpretation of the dark energy. The former case is analyzed considering a closed model based on a regular lattice of black holes using the Einstein equation in vacuum. LÄS MER