Sökning: "modified gravity"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden modified gravity.

  1. 1. Gravitational collapse in bimetric gravity

    Författare :Marcus Högås; Edvard Mörtsell; Tomi Koivisto; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Bimetric gravity; bigravity; modified gravity; gravitational collapse; Bimetrisk gravitation; modifierad gravitation; gravitationskollaps; Theoretical Physics; teoretisk fysik;

    Sammanfattning : Einstein’s theory of general relativity has been the prevailing theory of classical gravity for over a century. Its observational consistency is unparalleled. There are however a few (arguably) serious short-comings. LÄS MER

  2. 2. Cosmic tests of massive gravity

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

    Sammanfattning : 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. LÄS MER

  3. 3. Strings, Gravitons, and Effective Field Theories

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

    Sammanfattning : 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. LÄS MER

  4. 4. Geometry of interactions in ghost-free bimetric theory

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

    Sammanfattning : 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. LÄS MER

  5. 5. The BIG ghost

    Författare :Mikael von Strauss; Kjell Rosquist; Ariel Goobar; Edwin Langmann; Stockholms universitet; []
    Nyckelord :modified gravity; extra dimensions; cosmological constant;

    Sammanfattning : In this thesis we present work done in an analysis of models of brane induced gravity. These are higher dimensional generalizations of Einstein's General relativity where our universe is considered as a brane in a higher dimensional bulk and where the gravitational dynamics on the brane is enhanced. LÄS MER