We compute the parity violating three point amplitudes with one scalar leg in higher spin gravity and compare results with those of Chern-Simons matter theories. The three-point correlators of the free boson, free fermion, critical vector model and Gross-Neveu model are reproduced including the dependence on the Chern-Simons coupling. We also perform a simple test of the modified higher spin equations proposed in arXiv:1605.02662 [hep-th] and find that the results are consistent with the AdS/CFT correspondence.
Reformulating our recent result (arXiv:1007.1246 [hep-th]) in coordinate space we point out that no matter how regular is short-distance behavior of Green's function the entanglement entropy in the corresponding quantum field theory is always UV divergent. In particular, we discuss a recent example by Padmanabhan (arXiv:1007.5066 [gr-qc]) of a regular Green's function and show that provided this function arises in a field theory the entanglement entropy in this theory is UV divergent and calculate the leading divergent term.
We develop a manifestly supersymmetric version of the generalized unitarity cut method for calculating scattering amplitudes in N=4 SYM theory. We illustrate the power of this method by computing the one-loop n-point NMHV super-amplitudes. The result confirms two conjectures which we made in arXiv:0807.1095 [hep-th]. Firstly, we derive the compact, manifestly dual superconformally covariant form of the NMHV tree amplitudes for arbitrary number and types of external particles. Secondly, we show that the ratio of the one-loop NMHV to the MHV amplitude is dual conformal invariant.
We point out that in some situations it is possible to use matrix model techniques a la Dijkgraaf-Vafa to perturbatively compute D-brane instanton effects. This provides an explanation in terms of stringy instantons of the results in hep-th/0311181. We check this proposal in some simple scenarios. We point out some interesting consequences of this observation, such as the fact that it gives a perturbative way of computing stringy multi-instanton effects. It also provides a further interpretation of D-brane instantons as residual instantons of higgsed supergroups.
In this note, we review our construction of de Sitter vacua in type IIB flux compactifications, in which moduli stabilization and D-term uplifting can be combined consistently with the supergravity constraints. Here, the closed string fluxes fix the dilaton and the complex structure moduli while perturbative quantum corrections to the Kähler potential stabilize the volume Kahler modulus in an AdS_4-vacuum. Then, magnetized D7-branes provide consistent supersymmetric D-term uplifting towards dS_4. Based on hep-th/0602253.
We subject the phenomenologically successful large volume scenario of hep-th/0502058 to a first consistency check in string theory. In particular, we consider whether the expansion of the string effective action is consistent in the presence of D-branes and O-planes. Due to the no-scale structure at tree-level, the scenario is surprisingly robust. We compute the modification of soft supersymmetry breaking terms, and find only subleading corrections. We also comment that for large-volume limits of toroidal orientifolds and fibered Calabi-Yau manifolds the corrections can be more important, and we discuss further checks that need to be performed.
We develop the formalism discussed previously in hep-ph/0601209 and hep-ph/0605246 to construct a kinetic theory that provides insight into the earliest ``Glasma'' stage of a high energy heavy ion collision. Particles produced from the decay of classical fields in the Glasma obey a Boltzmann equation whose novel features include an inhomogeneous source term and new contributions to the collision term. We discuss the power counting associated with the different terms in the Boltzmann equation and outline the transition from the field dominated regime to the particle dominated regime in high energy heavy ion collisions.
We demonstrate the role of Drinfeld's quantum double D(G) as a spontaneously broken hidden symmetry in a large class of massive quantum field theories in 1+1 dimensions with compact symmetry group G. Our considerations are independent of exact integrability. The main technical ingredient is an assumption concerning the statistical independence of fields localized in spacelike separated regions which should hold in all reasonable massive models. The present note is an abridged version of hep-th/9606175.
Using the Fock-Schwinger proper time method, we calculate the induced Chern-Simons term arising from the Lorentz- and CPT-violating sector of quantum electrodynamics with a $b_μ\barψγ^μγ_5 ψ$ term. Our result to all orders in $b$ coincides with a recent linear-in-$b$ calculation by Chaichian et al. [hep-th/0010129 v2]. The coincidence was pointed out by Chung [Phys. Lett. {\bf B461} (1999) 138] and Pérez-Victoria [Phys. Rev. Lett. {\bf 83} (1999) 2518] in the standard Feynman diagram calculation with the nonperturbative-in-$b$ propagator.
Olaf Lechtenfeld, Alexander D. Popov, Bernd Spendig
In the presence of D-branes, fermionic N=2 strings in 2+2 dimensions can be coupled to a K"ahler NS-NS two-form B. We present the corresponding action which produces N=2 supersymmetric boundary conditions and discuss the Seiberg-Witten zero-slope limit. After recalling the constraints on the Chan-Paton gauge group, we demonstrate for U(n) groups that the open N=2 string with a nonzero B-field coincides on tree level with noncommutative self-dual Yang-Mills. Several misconceptions of hep-th/0011206 are corrected.
RR fields in string backgrounds including orientifold planes and branes on top of them are classified by K-theory. Following the idea introduced in hep-th/0103183, we also classify such fluxes by cohomology. Both of them are compared through the Atiyah-Hirzebruch Spectral Sequence. Some new correlations between branes on orientifold planes $Op^\pm$ and obstructions to the existence of some branes are found. Finally, we find a topological condition that avoid the presence of global gauge anomalies in lower dimensional systems.
The noncommutative bion core of Constable, Myers and Tafjord (hep-th/9911136) describes the BPS D1-D3 brane intersection (where a single bundle of D1-branes is attached to the D3 brane) in the nonabelian Born-Infeld theory of D1-branes. The possibility of extending this construction to BPS configurations with multiple separated parallel bundles of D1-branes attached to a single D3-brane is discussed. The problem is reduced to solving the Nahm equation with novel boundary conditions. A concrete, non-trivial solution is presented.
We summarize some results obtained on the problem of gauging the Wess--Zumino term of a d-dimensional bosonic sigma-model. We show that gauged WZ-like terms are in one-to-one correspondence with equivariant cocycles of the target space. By the same token, the obstructions to gauging a WZ term can be understood in terms of the equivariant cohomology of the target space and this allows us to use topological tools to derive some a priori vanishing theorems guaranteeing the absence of obstructions for a large class of target spaces and symmetry groups in the physically interesting dimensions d<=4. (This is an expository summary of the results of hep-th/9407149.)
We show that the diagonal light-like solution with 16 supersymmetries in eleven-dimensional supergravity derived in our previous paper (hep-th/0509173) can be generalised to non-diagonal solutions preserving the same number of supersymmetries. This class of solutions contains a subclass equivalent to the class of solutions found by Bin Chen that are dependent on the spatial-coordinates. Utilising these solutions, we construct toroidally compactified solutions that smoothly connect a static compactified region with a dynamically decompactifying region along a null hypersurface.