Sökning: "string compactifications"
Visar resultat 1 - 5 av 13 avhandlingar innehållade orden string compactifications.
1. 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
2. Cosmoparticle Physics and String Theory
Sammanfattning : 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. LÄS MER
3. 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
4. Pierced, Wrapped and Torn : Aspects of String Theory Compactifications
Sammanfattning : An outstanding problem in physics is to find a unified framework for quantum mechanics and general relativity. This is required for a better understanding of black holes and the early cosmology of the universe. String theory provides such a unification. In this thesis, we study aspects of compactifications of type IIB string theory. LÄS MER
5. Aspects of vacuum moduli in string theory
Sammanfattning : In this thesis we explore geometric aspects of the space of vacua in supersymmetric string compactifications. More specifically, we will look at heterotic strings compactified on Calabi-Yau manifolds and, separately, G2 structure manifolds. LÄS MER