Search for dissertations about: "extension of general relativity"

Showing result 1 - 5 of 8 swedish dissertations containing the words extension of general relativity.

  2. 1. Theoretical and numerical bimetric relativity

    Author : Francesco Torsello; Edvard Mörtsell; Eugeny Babichev; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; spin-2 fields; extension of general relativity; ghost-free bimetric theory; Hassan–Rosen bimetric relativity; numerical relativity; teoretisk fysik; Theoretical Physics;

    Abstract : General relativity (GR) is the standard physical theory describing gravitational interactions. All astrophysical and cosmological observations are compatible with its predictions, provided that unknown matter and energy components are included. These are called dark matter and dark energy. READ MORE

  4. 2. Cosmic tests of massive gravity

    Author : Jonas Enander; Edvard Mörtsell; Stefan Hofmann; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Modified gravity; massive gravity; cosmology; dark energy; dark matter; fysik; Physics;

    Abstract : Massive gravity is an extension of general relativity where the graviton, which mediates gravitational interactions, has a non-vanishing mass. The first steps towards formulating a theory of massive gravity were made by Fierz and Pauli in 1939, but it took another 70 years until a consistent theory of massive gravity was written down. READ MORE

  5. 3. Geometry of interactions in ghost-free bimetric theory

    Author : Mikica Kocic; Sayed Fawad Hassan; Tomi Koivisto; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Modified gravity; Interacting spin-2 fields; Bimetric theory; Massive gravity; teoretisk fysik; Theoretical Physics;

    Abstract : The ghost-free bimetric theory is an extension to general relativity where two metric tensors are used instead of one. A priori, the two metrics may not have compatible notions of space and time, which makes the formulation of the initial-value problem problematic. READ MORE

  6. 4. On the Einstein-Vlasov system

    Author : Mikael Fjällborg; Alexander Bobylev; Markus Kunze; Karlstads universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Einstein-Vlasov system; finite extension; monotone functions; MATHEMATICS; MATEMATIK; Matematik; Mathematics;

    Abstract : In this thesis we consider the Einstein-Vlasov system, which models a system of particles within the framework of general relativity, and where collisions between the particles are assumed to be sufficiently rare to be neglected. Here the particles are stars, galaxies or even clusters of galaxies, which interact by the gravitational field generated collectively by the particles. READ MORE

  7. 5. Strings, Gravitons, and Effective Field Theories

    Author : Igor Buchberger; Marcus Berg; Joseph A. Minahan; Karlstads universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; string theory; amplitudes; supersymmetry; particle phenomenology; BMSSM; modified gravity; bimetric; massive gravity; Lie algebras; ribbon categories; Physics; Fysik;

    Abstract : This thesis concerns a range of aspects of theoretical physics. It is composed of two parts. In the first part we motivate our line of research, and introduce and discuss the relevant concepts. In the second part, four research papers are collected. READ MORE