Sökning: "string"

Visar resultat 6 - 10 av 193 avhandlingar innehållade ordet string.

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

   Författare :Martin Olsson; Ulf Danielsson; Lárus Thorlacius; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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;

   Sammanfattning : 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. LÄS MER

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

   Författare :Johan Engquist; Joseph Minahan; Charlotte Kristjansen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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;

   Sammanfattning : 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. LÄS MER

4. 8. Cosmoparticle Physics and String Theory

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

   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

5. 9. Linking Chains Together : String Bits and the Bethe Ansatz

   Författare :Martin Lübcke; Konstantin Zarembo; Antti Niemi; Matthias Staudacher; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical physics; theoretical physics; string theory; string bit; Bethe ansatz; Teoretisk fysik; Physics; Fysik;

   Sammanfattning : This thesis is divided into two parts. In the first part we focus mainly on certain aspects of the AdS/CFT correspondence. The AdS/CFT correspondence is a proposed duality between Type IIB superstring theory on AdS5 x S5 and N = 4 supersymmetric Yang-Mills theory. LÄS MER

7. 10. Vacua in String Theory : de Sitter Space and Stability in Flux Compactifications

   Författare :Sergio C. Vargas; Ulf Danielsson; Alessandro Tomasiello; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; String theory; Cosmology; Flux Compactifications; Landscape; Swampland;

   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