Sökning: "string theory"
Visar resultat 6 - 10 av 103 avhandlingar innehållade orden string theory.
6. Vacua in String Theory : de Sitter Space and Stability in Flux Compactifications
Sammanfattning : Our understanding of cosmology has evolved radically in the last decades. Current models demand the presence of dark energy in our universe and the most favored candidate behind this component is a small positive cosmological constant that characterizes a de Sitter (dS) spacetime. LÄS MER
7. Holographic Wilson Loops : Quantum String Corrections
Sammanfattning : The gauge-string duality has been one of the most exciting areas in theoretical physics as it connects strongly coupled field theories with weakly interacting strings. The present thesis concerns the study of Wilson loops in this correspondence. LÄS MER
8. On string integrability : A journey through the two-dimensional hidden symmetries in the AdS/CFT dualities
Sammanfattning : 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. LÄS MER
9. Automorphic string amplitudes
Sammanfattning : 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. LÄS MER
10. Aspects of Yang-Mills Theory : Solitons, Dualities and Spin Chains
Sammanfattning : 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. LÄS MER