Isak Buhl-MortensenIsak Buhl-Mortensen

A thesis submitted  September 2017 for the degree of Doctor of Philosophy and defended November, 2017.

The PhD School of Science
Faculty of Science, Theoretical Particle Physics and Cosmology, Niels Bohr Institute, University of Copenhagen

Academic advisor:
Charlotte Kristjansen

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One-point Functions in AdS/dCFTandIntegrability

Super Yang-Mills with a co-dimension one defect is studied, in particular, the field theory setup that arises in the D3-probe-D5 brane construction of the Karch-Randal idea. We look at the case where k ≥ 2 D3-branes are absorbed by the D5, giving rise to a domain wall defect that separates the eld theory into an SU(N - k) theory and a broken SU(N) theory. The defect allows for interesting one-point functions in the SU(2) sub-sector already at tree-level. One-point functions in this sub-sector are computed, key results include the closed determinant formula at tree-level valid for all k, and subsequently a concise one-loop result for k = 2. The one-loop result is conjectured to be exact for the BMN vacuum trL1 . A major feat is the diagonalization of the bulk action around the fuzzy-funnel background, as it opens up for many novel tests of the AdS/dCFT correspondence. Results for the BMN one-point functions are compared with string theory in the double-scaling limit. Agreement is found at tree-level and subsequently an all loop conjecture is made based on integrability.

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