A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy February 2017. / In this dissertation we exploit the Ads slash CFT correspondence to describe a system of strings suspended between giant gravitons. The strings can be in an excited state. The excitations of the strings can be given a particle-like description and are known as magnons. The proposed gauge invariant operators used to construct a complete description of this system belong to the su(2) sector of the N = 4 SYM. Using an open spin chain description of the suspended strings, the states of the system we consider enjoy an SU 2j2)2 symmetry. By making use of this symmetry, we compute the all loop anomalous dimensions of these operators. The spectrum of the dilatation operator in the su(2) sector of the theory is reproduced in the dual gravity description. In the dual theory, the energies of the magnons are computed using strings in a background LLM geometry and the results are in complete agreement with the anomalous dimensions of the operators we have considered. Using the symmetries enjoyed by our system we achieve a complete determination - up to an overall phase - of the reection/scattering matrix between a boundary magnon and a bulk magnon. Thus, although the open boundary conditions of the spin chain spoil integrability. The two-loop subleading correction to the dilatation operator is also explored. This subleading term corresponds to a correction of the magnon energies. The computation of this subleading term requires consideration of the giant's backreaction on their excitations. We nd that this backreaction implies a nontrivial mixing of the dual operators and this mixing is characterized completely. / MT2017

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 117-118). Available also in a digital version from Dissertation Abstracts.

Not available / text

Classical gauge theories are studied for spherically symmetric monopole solutions. The Higgs field is taken in the adjoint representation and in the limit of vanishing self-interaction. The equations of motion can be represented by a Lax pair. Using techniques from group representation theory, explicit solutions are obtained in the case of the principal embedding of the symmetry group SU(2) in the bigger gauge group. The parameters of the solutions can be chosen to give finite fields everywhere, and the large r behaviour of the Higgs field, which determines the symmetry breaking, is discussed. Some low rank groups are studied as examples. Next, some properties of the non-principal SU(2) embeddings and their classification are discussed. These are then used to obtain more solutions, but the problem has not been solved for the most general case.

Bibliography: p. 169-172. / viii, 172 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Uses the tool of lattice regularisation to calculate the 2-point Euclidean Green's function in pure SU (3) Yang-Mills (quenched quantum chromodynamics), in Landau gauge. Adding improved gauge fixing and tree level correction to the improvement program developed by Symanzik [et al.], shows that the gluon propagator can be reliably calculated on lattices coarser than has hitherto been used. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2000?

Bibliography : p. 105-111 / xi, 111 p. : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1992

Bibliography: p. 169-172. / viii, 172 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Uses the tool of lattice regularisation to calculate the 2-point Euclidean Green's function in pure SU (3) Yang-Mills (quenched quantum chromodynamics), in Landau gauge. Adding improved gauge fixing and tree level correction to the improvement program developed by Symanzik [et al.], shows that the gluon propagator can be reliably calculated on lattices coarser than has hitherto been used. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2000?

Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2000? / Bibliography: p. 169-172.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1982. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (Dr. rer. nat.)--Rheinische Friedrich-Wilhelms-Universität Bonn, 2001. / Includes bibliographical references (p. 131-133).