Search for dissertations about: "tensionless strings"

Showing result 1 - 5 of 6 swedish dissertations containing the words tensionless strings.

  2. 1. Tensionless Strings and Supersymmetric Sigma Models : Aspects of the Target Space Geometry

    Author : Andreas Bredthauer; Ulf G. Lindström; Bengt E.W. Nilsson; Uppsala universitet; []
    Keywords : Theoretical physics; Theoretical Physics; String Theory; Tensionless Strings; Supergravity Backgrounds; Plane Wave; Supersymmetry; Non-linear Sigma Models; Generalized Complex Geometry; Teoretisk fysik;

    Abstract : In this thesis, two aspects of string theory are discussed, tensionless strings and supersymmetric sigma models.The equivalent to a massless particle in string theory is a tensionless string. Even almost 30 years after it was first mentioned, it is still quite poorly understood. READ MORE

  4. 2. Strings, boundary fermions and coincident D-branes

    Author : Linus Wulff; Ulf Lindström; Fawad Hassan; Dmitri Sorokin; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; string theory; open strings; D-branes; supersymmetry; non-abelian gauge theory; tensionless strings; Physics; Fysik;

    Abstract : The appearance in string theory of higher-dimensional objects known as D-branes has been a source of much of the interesting developements in the subject during the past ten years. A very interesting phenomenon occurs when several of these D-branes are made to coincide: The abelian gauge theory living on each brane is enhanced to a non-abelian gauge theory living on the stack of coincident branes. READ MORE

  5. 3. Strings as Sigma Models and in the Tensionless Limit

    Author : Jonas Persson; Ulf Lindström; Joseph Minahan; Fawad Hassan; Uppsala universitet; []
    Keywords : Theoretical physics; Theoretical Physics; String Theory; Tensionless Strings; Supergravity Backgrounds; Plane Wave; Extended Supersymmetry; Non-Linear Sigma Models; Generalized Complex Geometry; T-duality; Teoretisk fysik;

    Abstract : This thesis considers two different aspects of string theory, the tensionless limit of the string and supersymmetric sigma models with extended supersymmetry. First, the tensionless limit is used to find a IIB supergravity background generated by a tensionless string. The background has the characteristics of a gravitational shock-wave. READ MORE

  6. 4. Aspects of conformal strings

    Author : Panagiotis Saltsidis; Stephen Hwang; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; fysik;

    Abstract : String theory is the quantum theory in which the fundamental constituents are one-dimensional extended objects in contrast to the usual quantum theories in which the fundamental constituents are point particles. At present we know of only one way to spread out the gravitational interaction and cut off its divergencies without spoiling the consistency of the theory; string theory. READ MORE

  7. 5. 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 : 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;

    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