Report/Dissertation / PhD Thesis

PUBDB-2015-02760

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Dissecting CFT Correlators and String Amplitudes: Conformal Blocks and On-Shell Recursion for General Tensor Fields

Hansen, T. (Corresponding author)>Extern*

2015
Verlag Deutsches Elektronen-Synchrotron Hamburg

This record in other databases:

Please use a persistent id in citations: doi:10.3204/DESY-THESIS-2015-026

Report No.: DESY-THESIS-2015-026

Abstract: This thesis covers two main topics: the tensorial structure of quantum field theory correlators in general spacetime dimensions and a method for computing string theory scattering amplitudes directly in target space.In the first part tensor structures in generic bosonic CFT correlators and scattering amplitudes are studied. To this end arbitrary irreducible tensor representations of $SO(d)$ (traceless mixed-symmetry tensors) are encoded in group invariant polynomials, by contracting with sets of commuting and anticommuting polarization vectors which implement the index symmetries of the tensors. The tensor structures appearing in CFT$_d$ correlators can then be inferred by studying these polynomials in a $d+2$ dimensional embedding space. It is shown with an example how these correlators can be used to compute general conformal blocks describing the exchange of mixed-symmetry tensors in four-point functions, which are crucial for advancing the conformal bootstrap program to correlators of operators with spin.Bosonic string theory lends itself as an ideal example for applying the same methods to scattering amplitudes, due to its particle spectrum of arbitrary mixed-symmetry tensors. This allows in principle the definition of on-shell recursion relations for string theory amplitudes. A further chapter introduces a different target space definition of string scattering amplitudes. As in the case of on-shell recursion relations, the amplitudes are expressed in terms of their residues via BCFW shifts. The new idea here is that the residues are determined by use of the monodromy relations for open string theory, avoiding the infinite sums over the spectrum arising in on-shell recursion relations. Several checks of the method are presented, including a derivation of the Koba-Nielsen amplitude in the bosonic string. It is argued that this method provides a target space definition of the complete S-matrix of string theory at tree-level in a flat background in terms of a small set of conditions, without relying on any worldsheet computation.

Note: Universität Hamburg, Diss., 2015

---

Contributing Institute(s):

1. Uni Hamburg / Theorie (UNI/TH)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF3-611) (POF3-611)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2015

---

Database coverage:

---