Search for dissertations about: "perturbative string theory"

Showing result 1 - 5 of 22 swedish dissertations containing the words perturbative string theory.

2. 1. Cosmoparticle Physics and String Theory

   Author : Stefan Sjörs; Marcus Berg; Joseph Conlon; Stockholms universitet; []
   Keywords : 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

4. 2. Automorphic string amplitudes

   Author : Henrik Gustafsson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Eisenstein series; string theory; automorphic forms; U-duality; non-perturbative effects; Whittaker vectors; instantons;

   Abstract : This thesis explores the non-perturbative properties of higher derivative interactions appearing in the low-energy expansion of four-graviton scattering amplitudes in toroidal compactifications of type IIB string theory. We summarise the arguments for finding such higher derivative corrections in terms of automorphic forms using U-duality, supersymmetry and string perturbation theory. READ MORE

5. 3. On string integrability : A journey through the two-dimensional hidden symmetries in the AdS/CFT dualities

   Author : Valentina Giangreco Marotta Puletti; Konstantin Zarembo; Gleb Arutyunov; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; String Theory; AdS-CFT correspondence; Integrable Field theory; Sigma models; S-matrix; Factorized Scattering; Physics; Fysik; Mathematical physics; Matematisk fysik; Theoretical Physics; teoretisk fysik;

   Abstract : One of the main topics in the modern String Theory are the conjectured string/gauge (AdS/CFT) dualities. Proving such conjectures is extremely difficult since the gauge and string theory perturbative regimes do not overlap. In this perspective, the discovery of infinitely many conserved charges, i.e. READ MORE

6. 4. Automorphic forms and string theory: Small automorphic representations and non-perturbative effects

   Author : Henrik Gustafsson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; instantons; automorphic forms; automorphic representations; Eisenstein series; U-duality; non-perturbative effects; string theory;

   Abstract : This compilation thesis stems from a project with the purpose of determining non-perturbative contributions to scattering amplitudes in string theory carrying important information about instantons, black hole quantum states and M-theory. The scattering amplitudes are functions on the moduli space invariant under the discrete U-duality group and this invariance is one of the defining properties of an automorphic form. READ MORE

7. 5. Aspects of Yang-Mills Theory : Solitons, Dualities and Spin Chains

   Author : Lisa Freyhult; Antti Niemi; Poul Damgaard; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Theoretical physics; Theoretical Physics; Field theory; String theory; Yang-Mills; Effective models; Supersymmetry; Solitons; Fermion number; Duality; AdS CFT correspondence; Bethe ansatz; Teoretisk fysik; Physics; Fysik;

   Abstract : One of the still big problems in the Standard Model of particle physics is the problem of confinement. Quarks or other coloured particles have never been observed in isolation. Quarks are only observed in colour neutral bound states. The strong interactions are described using a Yang-Mills theory. READ MORE