Search for dissertations about: "string theory"

Showing result 1 - 5 of 84 swedish dissertations containing the words string theory.

  1. 1. String Theory at the Horizon : Quantum Aspects of Black Holes and Cosmology

    Author : Martin Olsson; Ulf Danielsson; Lárus Thorlacius; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Theoretical physics; theoretical physics; string theory; black holes; cosmology; de Sitter space; c=1 matrix models; 2D string theory; topological string theory; conifolds; 4D BPS black holes; Gödel universe; closed time-like curves; Teoretisk fysik; Physics; Fysik;

    Abstract : String theory is a unified framework for general relativity and quantum mechanics, thus being a theory of quantum gravity. In this thesis we discuss various aspects of quantum gravity for particular systems, having in common the existence of horizons. READ MORE

  2. 2. Torn, Spun and Chopped : Various Limits of String Theory

    Author : Fredric Kristiansson; Ulf Danielsson; Per Sundell; Bo Sundborg; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Theoretical physics; Theoretical physics; String theory; D-branes; Non-commutative open string theory; AdS CFT; Higher spin gauge theory; BMN; String bits; Fermion doubling; Teoretisk fysik; Physics; Fysik;

    Abstract : For the first time in the history of physics we stand in front of a theory that might actually serve as a unification of it all - string theory. It provides a self-consistent framework for gravity and quantum mechanics, which naturally incorporates matter and gauge interactions of the type seen in the standard model. READ MORE

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

    Author : Johan Engquist; Joseph Minahan; Charlotte Kristjansen; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; 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;

    Abstract : 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. READ MORE

  4. 4. Cosmoparticle Physics and String Theory

    Author : Stefan Sjörs; Marcus Berg; Joseph Conlon; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Supersymmetry; dark matter; cosmology; inflation; modifications of gravity; string theory; flux compactifications; perturbative string theory; teoretisk fysik; Theoretical Physics;

    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

  5. 5. New horizons in string theory : bubble babble in search of darkness

    Author : Suvendu Giri; Ulf Danielsson; Bert Vercnocke; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; String theory; black holes; dark energy; de Sitter; cosmological constant; M-theory; braneworld; anti de Sitter; Theoretical Physics; Teoretisk fysik;

    Abstract : It was discovered nearly two decades ago that we live in an accelerating universe that is dominated by dark energy. Understanding the origin of such an energy has turned out to be a very difficult open question in physics, and calls on the need for a fundamental theory like string theory. READ MORE