7861023
Holographic Renormalization
We systematically develop the procedure of holographic renormalization for RG flows dual to asymptotically AdS domain walls. All divergences of the on-shell bulk action can be cancelled by adding covariant local boundary counterterms determined by the near-boundary behavior of bulk fields. This procedure defines a renormalized action from which correlation functions are obtained by functional differentiation. The correlators are finite and well behaved at coincident points. Ward identities, corrected for anomalies, are satisfied. The correlators depend on parts of the solution of the bulk field equations which are not determined by near-boundary analysis. In principle a full nonlinear solution is required, but one can solve linearized fluctuation equations to define a bulk-to-boundary propagator from which 2-point correlation functions are easily obtained. We carry out the procedure explicitly for two known RG flows obtained from the maximal gauged D=5 supergravity theory, obtaining new results on correlators of vector currents and related scalar operators and giving further details on a recent analysis of the stress tensor sector. 1 M.Bianchi@damtp.cam.ac.uk 2 dzf@math.mit.edu kostas@feynman.princeton.edu
119040998
Instanton Effects in Supersymmetric Yang-Mills Theories on ALE Gravitational Backgrounds
In this letter we report on the computation of instanton-dominated correlation functions in supersymmetric YM theories on ALE spaces. Following the approach of Kronheimer and Nakajima, we explicitly construct the self-dual connection on ALE spaces necessary to perform such computations. We restrict our attention to the simplest case of an $SU(2)$ connection with lowest Chern class on the Eguchi-Hanson gravitational background.
15057808
(Non)perturbative tests of the AdS / CFT correspondence
I summarize perturbative and non-perturbative field theory tests of the holographic correspondence between type IIB superstring on AdS5 × S5 and N = 4 SYM theory. The holographic duality between D-instantons and YM instantons is briefly described. Non renormalization of two- and three-point functions of CPO's and their extremal and next-to-extremal correlators are then reviewed. Finally, partial non-renormalization of four-point functions of lowest CPO's is analyzed in view of the interpretation of short distance logarithmic behaviours in terms of anomalous dimensions of unprotected operators.
120082660
Toroidal compactification and symmetry breaking in open-string theories
Abstract In toroidal compactification of open-string theories, the background fields of the “parent” closed string (metric and antisymmetric tensor, with suitable restrictions) are accompanied by open-string Wilson lines. In the SO(32) superstring, these control the breaking of the Chan-Paton symmetry in a way that presents interesting analogies with the corresponding phenomenon in the heterotic string. An extension of the closed-string results to include contributions from the disk and the projective plane shows that these fields are genuine “moduli”, since their amplitudes vanish when the momenta are all scaled to zero.
94785817
Freezing E3-brane instantons with fluxes
E3-instantons that generate non-perturbative superpotentials in IIB N{script} = 1 compactifications have a much more frequent occurrence than currently believed. Worldvolume fluxes will typically lift the E3-brane geometric moduli and their fermionic superpartners, leaving only the two required universal fermionic zero-modes. We consistently incorporate SL(2, ℤ) monodromies and world-volume fluxes in the effective theory of the E3-brane fermions and study the resulting zero modes spectrum, highlighting the relation between F-theory and perturbative IIB results. This leads us to a IIB derivation of the index for generation of superpotential terms, which reproduces and generalizes available results. Furthermore, we show how E3 worldvolume fluxes can be explicitly constructed in a one-modulus compactification, such that the instanton has exactly two fermonic zero-modes. This construction is readily applicable to numerous scenarios. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
118440611
On stable higher spin states in heterotic string theories
We study properties of 1/2 BPS Higher Spin states in heterotic compactifications with extended supersymmetry. We also analyze non BPS Higher Spin states and give explicit expressions for physical vertex operators of the first two massive levels. We then study on-shell tri-linear couplings of these Higher Spin states and confirm that BPS states with arbitrary spin cannot decay into lower spin states in perturbation theory. Finally, we consider scattering of vector bosons off higher spin BPS states and extract form factors and polarization effects in various limits.
56038769
BPS Wilson loops and Bremsstrahlung function in ABJ(M): a two loop analysis
A bstractWe study a family of circular BPS Wilson loops in $ \mathcal{N} $ = 6 super Chern-Simons-matter theories, generalizing the usual 1/2-BPS circle. The scalar and fermionic couplings depend on two deformation parameters and these operators can be considered as the ABJ(M) counterpart of the DGRT latitudes defined in $ \mathcal{N} $ = 4 SYM. We perform a complete two-loop analysis of their vacuum expectation value, discuss the appearance of framing-like phases and propose a general relation with cohomologically equivalent bosonic operators. We make an all-loop proposal for computing the Bremsstrahlung function associated to the 1/2-BPS cusp in terms of these generalized Wilson loops. When applied to our two-loop result it reproduces the known expression. Finally, we comment on the generalization of this proposal to the bosonic 1/6-BPS case.
118635378
From correlators to Wilson loops in Chern-Simons matter theories
We study n-point correlation functions for chiral primary operators in three dimensional supersymmetric Chern-Simons matter theories. Our analysis is carried on in $ \mathcal{N} = 2 $ superspace and covers $ \mathcal{N} = 2,3 $ supersymmetric CFT’s, the $ \mathcal{N} = 6 $ ABJM and the $ \mathcal{N} = 8 $ BLG models. In the limit where the positions of adjacent operators become light-like, we find that the one-loop n-point correlator divided by its tree level expression coincides with a light-like n-polygon Wilson loop. Remarkably, the result can be simply expressed as a linear combination of five dimensional two-mass easy boxes. We manage to evaluate the integrals analytically and find a vanishing result, in agreement with previous findings for Wilson loops.
80725226
Differences in the radiosensitivity of male germ cells determined in various strains of mice
119567264
Four‐points two‐loop scattering amplitude in ABJM theory
Within the = 2 superspace perturbative formulation of ABJM theory, we derive the set of scalar Feynman integrals describing the four-point scattering amplitude of chiral matter fields. Using dimensional regularization (D = 3 - 2ϵ), we evaluate the integrals on-shell and we compare the result with that of a Wilson-loop computed in a light-like tetragon contour: we find matching results between both calculations after identifying the kinematical invariants. We discuss further implications and open questions. This work is a contribution to the proceedings of the ‘XVIIth European Workshop on String Theory 2011’ held in Padua, Italy, on September 2011.
118517951
The conformal manifold of Chern-Simons matter theories
We determine perturbatively the conformal manifold of $ \mathcal{N} = 2 $ Chern-Simons matter theories with the aim of checking in the three dimensional case the general prescription based on global symmetry breaking, recently introduced in [1–3]. We discuss in details few remarkable cases like the $ \mathcal{N} = 6 $ ABJM theory and its less supersymmetric generalizations with/without flavors. In all cases we find perfect agreement with the predictions of global symmetry breaking prescription. For unflavored theories the conformal manifold is a three dimensional compact surface. This feature is peculiar of three dimensions, as it has no direct analogue in four dimensional supersymmetric models.