Search

Lorentz-invariant massive gravity is usually associated with a strong coupling scale Λ 3 . By including non-trivial effects from the Stückelberg modes, we show that about these vacua, one can push the strong coupling scale to higher values and evade the linear vDVZ-discontinuity. For generic parameters of the theory and generic vacua for the Stückelberg fields, the Λ 2 -decoupling limit of the theory is well-behaved and free of any ghost or gradient-like instabilities. We also discuss the implications for nonlinear sigma models with Lorentzian target spaces.

We conjecture the form of the one-loop determinants for localized gauge theories with eight supersymmetries on $d$-dimensional spheres. Combining this with results for the localized action, we investigate the strong coupling behavior in the large $N$ limit for a continuous range of $d$. In particular, we find the $N$ dependence of the free energy for supersymmetric Yang-Mills with only a vector multiplet in $3, Comment: 17 pages; v2: Typos corrected

We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics., Comment: v2: 19 pages, expanded version accepted to JHEP

We consider Virasoro conformal blocks in the large central charge limit. There are different regimes depending on the behavior of the conformal dimensions. The most simple regime is reduced to the global sl(2, C) conformal blocks while the most complicated one is known as the classical conformal blocks. Recently, Fitzpatrick, Kaplan, and Walters showed that the two regimes are related through the intermediate stage of the so-called heavy-light semiclassical limit. We study this idea in the particular case of the 5-point conformal block. To find the 5-point global block we use the projector technique and the Casimir operator approach. Furthermore, we discuss the relation between the global and the heavy-light limits and construct the heavy-light block from the global block. In this way we reproduce our previous results for the 5-point perturbative classical block obtained by means of the monodromy method., Comment: 19 pages, v2: minor corrections, typos removed; v3: more comments, extended Introduction and Conclusion, refs added, journal version

We describe a new approach to computing the chiral part of correlation functions of stress-tensor supermultiplets in N = 4 $$ \mathcal{N}=4 $$ SYM that relies on symmetries, analytic properties and the structure of the OPE only. We demonstrate that the correlation functions are given by a linear combination of chiral N = 4 $$ \mathcal{N}=4 $$ superconformal invariants accompanied by coefficient functions depending on the space-time coordinates only. We present the explicit construction of these invariants and show that the six-point correlation function is fixed in the Born approximation up to four constant coefficients by its symmetries. In addition, the known asymptotic structure of the correlation function in the light-like limit fixes unambiguously these coefficients up to an overall normalization. We demonstrate that the same approach can be applied to obtain a representation for the six-point NMHV amplitude that is free from any auxiliary gauge fixing parameters, does not involve spurious poles and manifests half of the dual superconformal symmetry.

We derive a general resummation formula for transverse-momentum distributions of hard processes at the leading logarithmic level in the high-energy limit, to all orders in the strong coupling. Our result is based on a suitable generalization of high-energy factorization theorems, whereby all-order resummation is reduced to the determination of the Born-level process but with incoming off-shell gluons. We validate our formula by applying it to Higgs production in gluon fusion in the infinite top mass limit. We check our result up to next-to-leading order by comparison to the high energy limit of the exact expression and to next-to-next-to leading by comparison to NNLL order trasverse momentum (Sudakov) resummation, and we predict the high-energy behaviour at next$^3$-to-leading order. We also show that the structure of the result in the small transverse momentum limit agrees to all orders with general constraints from Sudakov resummation., Comment: 28 pages, 6 figures, Final version published in JHEP: several typos corrected (including in equations)

In this paper, using the localization technique we analyze the large N limit of the mass deformed Aharony-Bergman-Jafferis-Maldacena (ABJM) theory on the three sphere with a finite mass parameter and finite Chern-Simons levels. We find two different solutions of the saddle point equations in the large N limit. With these solutions we compute the free energy and find that there is a first order phase transition. Our results may predict a phase transition in the dual gravity theory., 25 pages,3 figures; v2: typos corrected, a comment on solution II added, footnotes added, references added

In this paper we investigate the possibility whether, in the extreme limit of high energies and large transverse distances, reggeon field theory might serve as an effective theory of high energy scattering for strong interactions. We analyse the functional renormalization group equations (flow equations) of reggeon field theory and search for fixed points in the space of (local) reggeon field theories. We study in complementary ways the candidate for the scaling solution, investigate its main properties and briefly discuss possible physical interpretations., Comment: 35 pages, 6 figures, LaTeX, typos corrected, reference added

We study high-energy jet production in the multi-Regge limit making use of the Monte Carlo event generator BFKLex which includes collinear improvements in the form of double-log contributions as presented in [1]. Making use of the anti-kt jet algorithm in the FastJet implementation, we present results for the average transverse momentum and azimuthal angle of the produced jets when two tagged forward/backward jets are present in the final state. We also introduce a new observable which accounts for the average rapidity separation among subsequent emissions. Results are presented, for comparison, at leading order and next-to-leading order, with the resummation of collinear double logs proposed in [2]., Comment: 12 pages, 3 figures

The fate of shift-symmetries in effective string models is considered beyond tree-level. Such symmetries have been proposed in the past as a way to maintain a hierarchically small Higgs mass and also play a role in schemes of cosmological relaxation. It is argued that on general grounds one expects shift-symmetries to be restored in the limit of certain asymmetric compactifications, to all orders in perturbation theory. This behaviour is verified by explicit computation of the Kaehler potential to one-loop order., Comment: 19 pages

Soft theorems for the form factors of 1/2-BPS and Konishi operator super-multiplets are derived at tree level in N = 4 $$ \mathcal{N}=4 $$ SYM theory. They have a form identical to the one in the amplitude case. For MHV sectors of stress tensor and Konishi operator supermultiplets loop corrections to soft theorems are considered at one loop level. They also appear to have universal form in the soft limit. Possible generalization of the on-shell diagrams to the form factors based on leading soft behavior is suggested. Finally, we give some comments on inverse soft limit and integrability of form factors in the limit q 2 → 0.

AdS black holes with hyperbolic horizons provide strong-coupling descriptions of thermal CFT states on hyperboloids. The low-temperature limit of these systems is peculiar. In this note we show that, in addition to a large ground state degeneracy, these states also have an anomalously large holographic complexity, scaling logarithmically with the temperature. We speculate on whether this fact generalizes to other systems whose extreme infrared regime is formally controlled by Conformal Quantum Mechanics, such as various instances of near-extremal charged black holes., Reference added. 14 pages, 3 figures

As described by Cachazo, He and Yuan, scattering amplitudes in many quantum field theories can be represented as integrals that are fully localized on solutions to the so-called scattering equations. Because the number of solutions to the scattering equations grows quite rapidly, the contour of integration involves contributions from many isolated components. In this paper, we provide a simple, combinatorial rule that immediately provides the result of integration against the scattering equation constraints for any M\"obius-invariant integrand involving only simple poles. These rules have a simple diagrammatic interpretation that makes the evaluation of any such integrand immediate. Finally, we explain how these rules are related to the computation of amplitudes in the field theory limit of string theory., Comment: 30 pages, 29 figures

In this paper, we study the single and double soft behaviors of tree level off-shell currents and on-shell amplitudes in nonlinear sigma model(NLSM). We first propose and prove the leading soft behavior of the tree level currents with a single soft particle. In the on-shell limit, this single soft emission becomes the Adler's zero. Then we establish the leading and sub-leading soft behaviors of tree level currents with two adjacent soft particles. With a careful analysis of the on-shell limit, we obtain the double soft behaviors of on-shell amplitudes where the two soft particles are adjacent to each other. By applying Kleiss-Kuijf (KK) relation, we further obtain the leading and sub-leading behaviors of amplitudes with two nonadjacent soft particles., Comment: 41 pages, 6 tables, 9 figures, minor revised, more content about nonadjacent double soft limit, update the references

The double-soft limit of gluon and graviton amplitudes is studied in four dimensions at tree level. In general this limit is ambiguous and we introduce two natural ways of taking it: A consecutive double-soft limit where one particle is taken soft before the other and a simultaneous limit where both particles are taken soft uniformly. All limits yield universal factorisation formulae which we establish by BCFW recursion relations down to the subleading order in the soft momentum expansion. These formulae generalise the recently discussed subleading single-soft theorems. While both types of limits yield identical results at the leading order, differences appear at the subleading order. Finally, we discuss double-scalar emission in $\mathcal{N}=4$ super Yang-Mills theory. These results should be of use in establishing the algebraic structure of potential hidden symmetries in the quantum gravity and Yang-Mills S-matrix., Comment: 31 pages, 6 figures. v2: typos corrected, references added

We glue four refined topological vertices to obtain the building block of 5D $U(2)$ quiver instanton partition functions. We take the 4D limit of the result to obtain the building block of 4D instanton partition functions which, using the AGT correspondence, are identified with Virasoro conformal blocks. We show that there is a choice of the parameters of the topological vertices that we start with, as well as the parameters and the intermediate states involved in the gluing procedure, such that we obtain Virasoro minimal model conformal blocks., 23 pages, improved the presentation, added introductory material, etc

Limits of families of conformal field theories are of interest in the context of AdS/CFT dualities. We explore here the large level limit of the two-dimensional N=(2,2) superconformal W_{n+1} minimal models that appear in the context of the supersymmetric higher-spin AdS3/CFT2 duality. These models are constructed as Kazama-Suzuki coset models of the form SU(n+1)/U(n). We determine a family of boundary conditions in the limit theories, and use the modular bootstrap to obtain the full bulk spectrum of N=2 super-W_{n+1} primaries in the theory. We also confirm the identification of this limit theory as the continuous orbifold C^n/U(n) that was discussed recently., 20 pages

We present a next-to-leading order (NLO) calculation of $t\bar{t}$ production in hadronic collisions interfaced to shower generators according to the POWHEG method. We start from an NLO result from previous work, obtained in the zero width limit, where radiative corrections to both production and decays are included. The POWHEG interface required an extension of the POWHEG BOX framework, in order to deal with radiation from the decay of resonances. This extension is fully general (i.e. it can be applied in principle to any process considered in the zero width limit), and is here applied for the first time. In order to perform a realistic simulation, we introduce finite width effects using different approximations, that we validated by comparing with published exact NLO results. We have interfaced our POWHEG code to the PYTHIA8 shower Monte Carlo generator. At this stage, we dealt with novel issues related to the treatment of resonances, especially with regard to the initial scale for the shower that needs to be set appropriately. This procedure affects, for example, the fragmentation function of the b quark, that we have studied with particular attention. We believe that the tool presented here improves over previous generators for all aspects that have to do with top decays, and especially for the study of issues related to top mass measurements that involve B hadrons or b jets. The work presented here also constitutes a first step towards a fully consistent matching of NLO calculations involving intermediate resonances decaying into coloured particles, with parton showers., Comment: Minor changes: improved few sentences, added 1 explanatory figure in sec. 1. Now it matches the version published in JHEP

We study homogeneous gravitational instantons, conventionally called the Hawking-Moss (HM) instantons, in bigravity theory. The HM instantons describe the amplitude of quantum tunneling from a false vacuum to the true vacuum. Corrections to General Relativity (GR) are found in a closed form. Using the result, we discuss the following two issues: reduction to the de Rham-Gabadadze-Tolley (dRGT) massive gravity and the possibility of preference for a large $e$-folding number in the context of the Hartle-Hawking (HH) no-boundary proposal. In particular, concerning the dRGT limit, it is found that the tunneling through the so-called self-accelerating branch is exponentially suppressed relative to the normal branch, and the probability becomes zero in the dRGT limit. As far as HM instantons are concerned, this could imply that the reduction from bigravity to the dRGT massive gravity is ill-defined., 20 pages, 2 figures, comments and references added

In this short note we use the flat space limit and the relation between the 4-pt correlation function of the bottom and top components of the stress tensor multiplet to constraint its stringy corrections at strong coupling in the planar limit. Then we use this four point function to compute corrections to the anomalous dimension of double trace operators of the Lagrangian density and to compute energy-energy correlators at strong coupling.

Using symmetry considerations, we derive Ward identities which relate the three point function of scalar perturbations produced during inflation to the scalar four point function, in a particular limit. The derivation assumes approximate conformal invariance, and the conditions for the slow roll approximation, but is otherwise model independent. The Ward identities allow us to deduce that the three point function must be suppressed in general, being of the same order of magnitude as in the slow roll model. They also fix the three point function in terms of the four point function, upto one constant which we argue is generically suppressed. Our approach is based on analyzing the wave function of the universe, and the Ward identities arise by imposing the requirements of spatial and time reparametrization invariance on it., 35 pages; Extra references and comments added, The version published in JHEP

We study the thermodynamic behaviour of the real β- and γ i -deformation of $$ \mathcal{N}=4 $$ Super Yang-Mills theory on $$ \mathbb{R}\times {\mathrm{S}}^3 $$ in the planar limit. These theories were shown to be the most general asymptotically integrable supersymmetric and non-supersymmetric field-theory deformations of $$ \mathcal{N}=4 $$ Super Yang-Mills theory, respectively. We calculate the first loop correction to their partition functions using an extension of the dilatation-operator and Polya-counting approach. In particular, we account for the one-loop finite-size effects which occur for operators of length one and two. Remarkably, we find that the $$ \mathcal{O}\left(\lambda \right) $$ correction to the Hagedorn temperature is independent of the deformation parameters, although the partition function depends on them in a non-trivial way.

We compute the supersymmetric Renyi entropy across an entangling three-sphere for five-dimensional superconformal field theories using localization. For a class of USp(2N) gauge theories we construct a holographic dual 1/2 BPS black hole solution of Euclidean Romans F(4) supergravity. The large N limit of the gauge theory results agree perfectly with the supergravity computations., Comment: 19 pages

We provide a complete and detailed study of the high-energy limit of four-parton scattering amplitudes in QCD, giving explicit results at two loops and higher orders, and going beyond next-to-leading logarithmic (NLL) accuracy. Building upon recent results, we use the techniques of infrared factorization to investigate the failure of the simplest form of Regge factorization, starting at next-to-next-to-leading logarithmic accuracy (NNLL) in ln(s/|t|). We provide detailed accounts and explicit expressions for the terms responsible for this breaking in the case of two-loop and three-loop quark and gluon amplitudes in QCD; in particular, we recover and explain a known non-logarithmic double-pole contribution at two-loops, and we compute all non-factorizing single-logarithmic singular contributions at three loops. Conversely, we use high-energy factorization to show that the hard functions of infrared factorization vanish in d = 4 to all orders in the coupling, up to NLL accuracy in ln(s/|t|). This provides clear evidence for the infrared origin of high-energy logarithms. Finally, we extend earlier studies to t-channel exchanges of color representations beyond the octet, which enables us to give predictions based on the dipole formula for single-pole NLL contributions at three and four loops., Comment: 48 pages

We construct four-dimensional N = 4 $$ \mathcal{N}=4 $$ super-Yang-Mills theories on a conic sphere with various background R-symmetry gauge fields. We study free energy and supersymmetric Rényi entropy using heat kernel method as well as localization technique. We find that the universal contribution to the partition function in the free field limit is the same as that in the strong coupling limit, which implies that it may be protected by supersymmetry. Based on the fact that, the conic sphere can be conformally mapped to S 1 × ℍ 3 $$ {\mathbb{S}}^1\times {\mathrm{\mathbb{H}}}^3 $$ and the R-symmetry background fields can be supported by the R-charges of black hole, we propose that the holographic dual of these theories are five-dimensional, supersymmetric STU topological black holes. We demonstrate perfect agreement between N = 4 $$ \mathcal{N}=4 $$ super-Yang-MillstheoriesintheplanarlimitandtheSTUtopologicalblackholes.

In the high energy Regge limit, the six gluons scattering amplitude is controlled by the adjoint BFKL eigenvalue and impact factor. In this paper we determine these two building blocks at any value of the 't Hooft coupling in planar $\cal{N}$=4 SYM theory. This is achieved by means of analytic continuations from the collinear limit, where similar all loops expressions were recently established. We check our predictions against all available data at weak and strong coupling., Comment: 30 pages plus appendices, 12 figures. References added; published version

We perform a systematic search for anti-de Sitter vacua of maximal supergravity with N > 2 $$ \mathcal{N}>2 $$ residual supersymmetries. We find that maximal supergravity admits two 1-parameter classes of N = 3 $$ \mathcal{N}=3 $$ and N = 4 $$ \mathcal{N}=4 $$ vacua, respectively. They are embedded, for the different values of an angular parameter, in the ω-rotated SO(8) N = 3 $$ \left(\mathcal{N}=3\right) $$ and SO(1, 7) ( N = 4 $$ \mathcal{N}=4 $$ and 3) gauged models. All vacua disappear in the ω → 0 limit. We determine the mass spectra and the AdS-supermultiplet structure. These appear to be the first and only N > 2 $$ \mathcal{N}>2 $$ supersymmetric AdS vacua in maximal supergravity, aside from the N = 8 $$ \mathcal{N}=8 $$ vacua of the SO(8)-gauged models. We also prove on general grounds that no such vacua can exist for 4 < N < 8 $$ 4

We initiate an exploration of the physics and geometry of the amplituhedron, starting with the simplest case of the integrand for four-particle scattering in planar N=4 SYM. We show how the textbook structure of the unitarity double-cut follows from the positive geometry. We also use the geometry to expose the behavior of the multicollinear limit, providing a direct motivation for studying the logarithm of the amplitude. In addition to computing the two and three-loop integrands, we explore various lower-dimensional faces of the amplituhedron, thereby computing non-trivial cuts of the integrand to all loop orders., Comment: 34 pages, 23 figures

We present some computations of higher rank refined Donaldson-Thomas invariants on local curve geometries, corresponding to local D6-D2-D0 or D4-D2-D0 configurations. A refined wall-crossing formula for invariants with higher D6 or D4 ranks is derived and verified to agree with the existing formulas under the unrefined limit. Using the formula, refined invariants on the $(-1,-1)$ and $(-2,0)$ local rational curve with higher D6 or D4 ranks are computed., Comment: 17 pages

We consider a system consisting of a pair of D3 branes intersecting each other along a line such that half of the 16 supersymmetries are preserved. We then study the existence of magnetic monopole solutions corresponding to a D1-brane suspended between these D3 branes. We consider this problem in the zero slope limit where the tilt of the D3-branes is encoded in the uniform gradient of the adjoint scalar field. Such a system is closely related to the non-abelian flux background considered originally by van Baal. We provide three arguments supporting the existence of a single magnetic monopole solution. We also comment on the relation between our construction and a recent work by Mintun, Polchinski, and Sun., Comment: 16 pages, 1 figure, minor typos fixed. Reference added

We study the low energy effective theory of two sets of D3-branes overlapping in 1+1 dimensions, recently considered by Mintun, Polchinski, and Sun. In the original treatment by MPS, by studying the properties of magnetic solitons, the low energy effective field theory was found to require some ultraviolet completion, possibly involving full string dynamics. Recently in a companion paper, it was shown that by scaling the angle between the D3-branes and the D3'-branes in the zero slope limit in specific way, one can find simpler effective field theory which consists of a single tower of Regge trajectory states and yet is ultraviolet complete and non-singular. In this article, we study this model by further studying a limit which recovers the MPS dynamics from this non-singular construction. We approach this issue from a holographic perspective, where we consider a stack of $N$ D3-branes overlapping with a single D3'-brane, and treat that D3'-brane as a probe in the $AdS_5 \times S^5$ dual. In general, the D3'-brane probe supports a magnetic monopole as a non-singular soliton configuration, but in the limit where the MPS dynamics is recovered, the soliton degenerates. This is consistent with the idea that the effective dynamics in the MPS setup is incomplete, but that it can be completed with a single tower of Regge trajectory states., Comment: 24 pages, 2 figures

As holographic description of BPS Wilson loops in ${\cal N}=3$ flavored ABJM theory with $N_f=k=1$, BPS M2-branes in $AdS_4\times N(1, 1)$ are studied in details. Two $1/3$-BPS membrane configurations are found. One of them is dual to the $1/3$-BPS Wilson loop of Gaiotto-Yin type. The regulated membrane action captures precisely the leading exponential behavior of the vacuum expectation values of $1/3$-BPS Wilson loops in the strong coupling limit, which was computed before using supersymmetric localization technique. Moreover, there is no BPS membrane with more supersymmetries in the background, under quite natural assumption on the membrane worldvolume. This suggests that there is no Wilson loop preserving more than 1/3 supersymmetries in such flavored ABJM theory., v3, 19 pages, no figures, typoes fixed

We give next-to-next-to-leading order (NNLO) predictions for the Higgs production cross section at large transverse momentum in the threshold limit. Near the partonic threshold, all radiation is either soft or collinear to the final state jet which recoils against the Higgs boson. We find that the real emission corrections are of moderate size, but that the virtual corrections are large. We discuss the origin of these corrections and give numerical predictions for the transverse-momentum spectrum. The threshold result is matched to the known NLO result and implemented in the public code PeTeR., Comment: 17 pages, 9 Figures; v2: journal version, correction in the qg channel

We found a few typos as well as some errors in some of the chirality structures due to wrongly reading off the result from FormCalc. The final results are not affected, since these chirality structures do not contribute to the strongest constraints which set the limit for this model. The upper index of the momentum q in eq. (4.2) should be a lower index, qν , and the indices of the masses mli (mlj ) in the expression of σL (σR) in eq. (4.3) should read mlj (mli). The exponent of (tam − 1) in the denominator of the expressions for A L,R 1 in eqs. (4.9a) and (A.2a) should read 4 instead of 2

We study twist operators in higher dimensional CFT's. In particular, we express their conformal dimension in terms of the energy density for the CFT in a particular thermal ensemble. We construct an expansion of the conformal dimension in power series around n=1, with n being replica parameter. We show that the coefficients in this expansion are determined by higher point correlations of the energy-momentum tensor. In particular, the first and second terms, i.e. the first and second derivatives of the scaling dimension, have a simple universal form. We test these results using holography and free field theory computations, finding agreement in both cases. We also consider the `operator product expansion' of spherical twist operators and finally, we examine the behaviour of correlators of twist operators with other operators in the limit n ->1., 44 pages, 2 figures

Updated LHC data on the new 126 GeV boson during the 7 and 8 TeV runnings strengthen the standard model Higgs boson interpretation further. Through the global $\chi^2$ analysis, we investigate whether the new particle could be one of the scalar particles in two Higgs doublet models. Four types (Type I, II, X and Y) are comprehensively studied. Taking the recent analysis on the spin-parity of the new boson, we consider two scenarios: the new boson is either the light CP-even one ($h^0$) or the heavy CP-even one ($H^0$). It is found that both scenarios are consistent with the new data, not only in the parameter regions near the decoupling limit but also in other regions far from the decoupling limit. In addition, the current data are compatible with the possibility that the light Higgs boson $h^0$ is hidden in the mass window of 90-100 GeV. The diphoton or $\tau\tau$ channel can provide a probe of this possibility by the enhanced signal rates., Comment: To appear in JHEP

We consider the field theory describing the scaling limit of the Potts quantum spin chain using a combination of two approaches. The first is the renormalized truncated conformal space approach (TCSA), while the second one is a new thermodynamic Bethe Ansatz (TBA) system for the excited state spectrum in finite volume. For the TCSA we investigate and clarify several aspects of the renormalization procedure and counter term construction. The TBA system is first verified by comparing its ultraviolet limit to conformal field theory and the infrared limit to exact S-matrix predictions. We then show that the TBA and the renormalized TCSA match each other to a very high precision for a large range of the volume parameter, providing both a further verification of the TBA system and a demonstration of the efficiency of the TCSA renormalization procedure. We also discuss the lessons learned from our results concerning recent developments regarding the low-energy scattering of quasi-particles in the quantum Potts spin chain., Comment: 39 pages, 5 eps figures. v2: reference added. v3: several misprints corrected, and an important step in the derivation of counter terms (in section 3.4.1) is explained in more detail

In this paper we continue our analysis of arXiv:1308.1478[hep-th] and study in detail the parameter space of three families of doubly spinning black ring solutions: balanced black ring, unbalanced ring and dipole-charged balanced black rings. In all these three families the Extremal Vanishing Horizon (EVH) ring appears in the vanishing limit of the dimensionful parameter of the solution which measures the ring size. We study the near horizon limit of the EVH black rings and for all three cases we find a (pinching orbifold) AdS$_3$ throat with the AdS$_3$ radius $\ell^2=8 G_5 M/(3\pi)$ where $M$ is the ring mass and $G_5$ is the 5d Newton constant. We also discuss the near horizon limit of near-EVH black rings and show that the AdS$_3$ factor is replaced with a generic BTZ black hole. We use these results to extend the EVH/CFT correspondence for black rings, a 2d CFT dual to near-EVH black rings., Comment: 30 pages

In this short note I show that the soft limit for colour-ordered tree-level YangMills amplitudes contains a sub-leading divergent term. This term is analogous to those found recently by Cachazo and Strominger for tree-level gravity amplitudes.

The moderately large value of θ 13 , measured recently by reactor experiments, is very welcome news for the future neutrino experiments. In particular, the NO ν A experiment, with 3 years each of ν and v ¯ $$ \overline{v} $$ runs, will be able to determine the mass hierarchy if one of the following two favourable combinations is true: normal hierarchy with −180° ≤ δ CP ≤ 0 or inverted hierarchy with 0 ≤ δ CP ≤ 180°. In this report, we study the hierarchy reach of the first 3 years of NO ν A data. Since sin 2 2 θ 23 is measured to be non-maximal, θ 23 can be either in the lower or higher octant. Pure ν data is affected by θ 13 -hierarchy and octant-hierarchy degeneracies, which limit the hierarchy sensitivity of such data. A combination of ν and v ¯ $$ \overline{v} $$ data is not subject to these degeneracies and hence has much better hierarchy discrimination capability. We find that, with a 3 year ν run, hierarchy determination is possible for only two of the four octant-hierarchy combinations. Equal 1.5 year runs in ν and v ¯ $$ \overline{v} $$ modes give good hierarchy sensitivity for all the four combinations.

This paper considers the higher derivative terms in the effective action of type II string theory and in particular the behaviour of the automorphic forms they contain in all the different possible limits of the string parameters. The automorphic forms are thought to obey Poisson equations which contain the Laplacian defined on the coset space to which the scalars fields belong and we compute this Laplacian in all the possible string theory limits. We also consider these Poisson equations in the decompactification limit of a single dimension and by making two assumptions, one on the generic form of this equation and the other on the behaviour of the automorphic forms in this limit, we find strong constraints on the allowed form of this differential equation. We show that these constraints allow one to recover much of what was previously known about the automorphic forms corresponding to terms in the effective action that have fourteen or fewer space-time derivatives in a simple way., Comment: 47 pages, references added and typos corrected

For the proposed duality relating a family of $ \mathcal{N} $ = 4 superconformal coset models to a certain supersymmetric higher spin theory on AdS 3 , the asymptotic symmetry algebra of the bulk description is determined. It is shown that, depending on the choice of the boundary charges, one may obtain either the linear or the non-linear superconformal algebra on the boundary. We compare the non-linear version of the asymptotic symmetry algebra with the non-linear coset algebra and find non-trivial agreement in the ’t Hooft limit, thus giving strong support for the proposed duality. As a by-product of our analysis we also show that the $ {{\mathcal{W}}_{\infty }} $ symmetry of the coset theory is broken under the exactly marginal perturbation that preserves the $ \mathcal{N} $ = 4 superconformal algebra.

We analyze instantons in the very strongly coupled large-$N$ limit ($N\to\infty$ with $g^2$ fixed) of large-$N$ gauge theories, where the effect of the instantons remains finite. By using the exact partition function of four-dimensional ${\cal N}=2^*$ gauge theories as a concrete example, we demonstrate that each instanton sector in the very strongly coupled large-$N$ limit is related to the one in the 't Hooft limit ($N\to\infty$ with $g^2N$ fixed) through a simple analytic continuation. Furthermore we show the equivalence between the instanton partition functions of a pair of large-$N$ gauge theories related by an orbifold projection. This can open up a new way to analyze the partition functions of low/non-supersymmetric theories. We also discuss implication of our result to gauge/gravity dualities for M-theory as well as a possible application to large-$N$ QCD., Comment: 10 pages

We determine the bosonic part of the superstring sigma model Lagrangian on $\eta$-deformed AdS5 x S5, and use it to compute the perturbative world-sheet scattering matrix of bosonic particles of the model. We then compare it with the large string tension limit of the q-deformed S-matrix and find exact agreement., Comment: 23 pages, 1 figure. Misprint in (3.18) corrected

We compute the next-to-leading order (NLO) QCD corrections to the $1 \to 2$ splitting amplitudes in different dimensional regularization (DREG) schemes. Besides recovering previously known results, we explore new DREG schemes and analyze their consistency by comparing the divergent structure with the expected behavior predicted by Catani's formula. Through the introduction of scalar-gluons, we show the relation among splittings matrices computed using different schemes. Also, we extended this analysis to cover the double collinear limit of scattering amplitudes in the context of QCD+QED., Comment: 61 pages, 14 figures. Final version published in JHEP

We study the validity of effective field theory (EFT) interpretations of monojet searches for dark matter at the LHC for vector and axial-vector interactions. We show that the EFT approach is valid when the mediator has mass m_med greater than 2.5 TeV. We find that the current limits on the contact interaction scale Lambda in the EFT apply to theories that are perturbative for dark matter mass m_DM < 800 GeV. However, for all values of m_DM in these theories, the mediator width is larger than the mass, so that a particle-like interpretation of the mediator is doubtful. Furthermore, consistency with the thermal relic density occurs only for 170, Comment: 23 pages, 7 figures

Using exact results obtained from localization on S^4, we explore the large N limit of N=2 super-Yang-Mills theories with massive matter multiplets. We focus on three cases: N=2* theory, describing a massive hypermultiplet in the adjoint representation, SU(N) super-Yang-Mills with 2N massive hypermultiplets in the fundamental, and super-QCD with massive quarks. When the radius of the four-sphere is sent to infinity the theories at hand are described by solvable matrix models, which exhibit a number of interesting phenomena including quantum phase transitions at finite 't Hooft coupling.

In this paper we consider gauged N = 2 supergravities which arise in the low-energy limit of type II string theories and study examples which exhibit spontaneous partial supersymmetry breaking. For the quantum STU model we derive the scalar field space and the scalar potential of the N = 1 supersymmetric low-energy effective action. We also study the properties of the Minkowskian N = 1 supersymmetric ground states for a broader class of supergravities including the quantum STU model.

We consider a particular case of the 3-point function of local single-trace operators in the scalar sector of planar $ \mathcal{N}=4 $ supersymmetric Yang-Mills, where two of the fields are su(3) type, while the third one is su(2) type. We show that this tree-level 3-point function can be expressed in terms of scalar products of su(3) Bethe vectors. Moreover, if the second level Bethe roots of one of the su(3) operators is trivial (set to infinity), this 3- point function can be written in a determinant form. Using the determinant representation, we evaluate the structure constant in the semi-classical limit, when the number of roots goes to infinity.

In this paper, we study the properties of the colored HOMFLY polynomials via HOMFLY skein theory. We prove some limit behaviors and symmetries of the colored HOMFLY polynomial predicted in some physicists' recent works., 21 pages, 3 figures