Aspects of Higher Spin Theory

May 23, 2016, 8:00 AM → May 25, 2016, 6:35 PM Europe/Berlin

E.0.11 (Max-Planck-Institut für Astrophysik (MPA))

Igor Klebanov, Ivo Sachs, Johanna Erdmenger, Mikhail Vasiliev, Simone Giombi

The topical workshop "Aspects of Higher-spin theories" from 23rd to 25th May 2016 will bring together experts on higher-spin theories, conformal field theories, AdS/CFT correspondence and string theory. It will focus on Foundations of higher-spin theories AdS/CFT dualities in diverse dimensions Quantum properties of higher-spin theories Higher-spin theories and string theory Broken higher-spin symmetries and condensed matter physics A conference dinner (included) is planned on the second evening of the workshop. The workshop is a part of the MIAPP programme "HIGHER-SPIN THEORY AND DUALITY" which will take place 2 May – 27 May 2016.

Flyer/Schedule Aspects_of_higher_spin_theory.pdf

Poster http://www.munich-iapp.de/fileadmin/user_upload/MIAPP/ASPECTS_HIGHERSPIN.pdf

Monday, May 23

Matthias Gaberdiel: "The structure of the stringy symmetry algebra"

slides Gaberdiel.pdf

Soo Jong Rey: “(Partially) Massless and Massive Higher Spins from Anti-de Sitter Waveguide”

In this talk, I explain mechanism for generating massless, partially massless and massive higher spin fields in d-dimensional anti-de Sitter space.I start from massless higher spin fields in (d+1)-dimensional anti-de Sitter space and Kaluza-Klein compactify to d-dimesional anti-de Sitter space on an interval (AdS waveguide).I demonstrate that, to obtain partially massless higher spin fields, boundary conditions at the end of interval must involve spectrum-dependent, equivalently, higher-derivative boundary conditions. If time permits, I also demonstrate how the partially massless Higgs mechanism works from the viewpoint of dual CFT.

slides Rey.pdf

10:30 AM Coffee break

Alejandra Castro: "Higher Spin Black Holes"

Overview of recent progress on non-perturbative aspects of higher spin theories in three dimensions with emphasis on black holes.
The two main results that will be discussed are:
1) novel properties of extremal and susy solutions, and
2) Lorentzian features of eternal higher spin black holes.

Sasha Zhiboedov: “The S-matrix Bootstrap and The Leading Regge Trajectory”

We consider a tree-level meromorphic, unitary and crossing symmetric scattering amplitude. We set up bootstrap equations and use them together with unitarity to constrain the asymptotic form of the leading Regge trajectory.

12:30 PM Lunch

Slava Didenko: "Invariant functionals and charges in HS theory"

We review the construction of invariant functionals and conserved charges in nonlinear HS theory. In context of AdS/CFT correspondence we discuss a proposal for boundary correlation functions defined via an invariant functional 4-form. The construction of HS conserved charges is tested on some HS black hole solutions leading to a standard ADM values at lowest level in perturbation theory.

Nicolas Boulanger: "Duality in gravity and higher-spin gauge theory"

We present the off-shell dualization of massless spin-2 gauge theory in AdS background obtained in 1512.09060 [hep-th].

slides Boulanger_Slides.pdf

Eric Perlmutter: "Bootstrapping the Space of Higher Spin Theories"

We place new constraints on the landscape of 2d conformal field theories with higher spin currents, and on higher spin theories in AdS_3, using Lorentzian bootstrap methods. We show that unitary 2d CFTs with large central charge, light primary operators and a finite tower of higher spin currents cannot exist, and likewise for their putative AdS_3 dual theories of higher spin gravity. Theories with infinite towers of currents evade this conclusion, consistent with a potential embedding into string theory.

4:00 PM Coffee

Tristan McLoughlin: Conformal Higher Spins and Twistor Actions

slides Munich_2016_mcloughlin.pdf

Tuesday, May 24

Xavier Bekaert: “Conformal vs Gauge Symmetry of (Partially) Massless Fields”

The vector space of Killing tensors forms a module of the Lie algebra of global symmetries. Since the classification of global reducibility parameters is generically easier than the classification of global symmetries, this fact can be used to constrain the latter when knowing the former. This scheme allows one to show that, in terms of potentials, massless higher spin gauge fields in Minkowski space and partially-massless fields in (A)dS space are not conformal for spin strictly greater than one, while in terms of curvatures, maximal-depth partially-massless fields in four dimensions are also not conformal.

slides MIAPP2016_Bekaert.pdf

Arkady Tseytlin: "On higher string scattering in flat space"

Review of some recent work (arXiv:1603.06273 with D. Ponomarev) on computation of simple scattering amplitudes in flat space higher spin theory.

slides tseytlin-talk.24.05.2016.pdf

10:30 AM Coffee break

Antal Jevicki: "Bi-Local Holography in Low Dimensions "

We will describe recent work on Large N Vector model correspondence
involving the 1 dimensional Sachdev-Ye-Kitaev model and its AdS2 dual.

slides Jevicki.pdf

Glenn Barnich: “Finite BMS transformations”

After a review of holographic features of general relativity in 3 and 4 dimensions, I will show how to derive the transformation laws of the Bondi mass and angular momentum aspects under finite supertranslations, superrotations and complex Weyl rescalings.

slides BarnichMunich2016bis.pdf

12:30 PM Lunch

Joris Raeymaekers: "Coupling matter to the higher spin square"

Gaberdiel and Gopakumar recently proposed that the tensionless limit of string theory on $AdS_3 \times S^3 \times T^4$ takes the form of a higher spin theory with a gauge algebra that is called the `higher spin square'. Here we will couple a bulk matter field to the higher spin square gauge theory and show that its particle spectrum accounts for the entire untwisted sector of the dual symmetric orbifold CFT.

slides Raeymaekers.pdf

Zhenya Skvortsov: "On the structure of higher-spin interactions"

slides LightCorn-Skvortsov.pdf

Xi Yin: Carving out 2D superconformal field theories

slides Xi_Yin.pdf

4:00 PM Coffee break

Andrea Campoleoni: "Hamiltonian derivation of higher-spin charges"

We construct asymptotic charges for both bosonic and fermionic free higher-spin fields on anti de Sitter backgrounds of any dimension. We work within the Hamiltonian setup: we first revisit the Hamiltonian presentation of Fronsdal's action and then we provide boundary conditions on fields and explicit expressions for the charges.

slides Campoleoni.pdf

Conference Dinner

Metro Line U6 to "Klinikum Großhadern"
Stop: Giselastraße

Wednesday, May 25

Marc Henneaux: "Twisted Self-Duality and SO(2) Electric-Magnetic Duality for Gravity and Higher Spin Gauge Fields"

We provide manifestly duality-symmetric formulations of linearized gravity and higher spin gauge fields. This requires introducing appropriate prepotentials and leads to a loss of manifest spacetime covariance. The prepotentials intriguingly exhibit higher spin Weyl symmetry for all spins. The analysis is motivated by the study of the conjectured hidden symmetries of gravity (such as E(10)), which have duality buit in.

slides Henneaux.pdf

Ergin Sezgin: “Frobenius-Chern-Simons Gauge Theory”

We show that the most general cubic action for a set of even and odd forms on an odd-dimensional noncommutative manifold valued in an internal associative algebra H is given by a natural generalization of the Frobenius-Chern-Simons (FCS) model proposed in arXiv:505.04957 as a minimal bosonic 4D higher spin gravity theory. The result is a cubic FCS action for a superconnection valued in H X F where F is a Z2-graded quasi-Frobenius algebra. Unital element not necessary of the general model is subsequently introduced. An example of such a model is given based on Clifford algebra C_2n and it is shown to provide a nontrivial FCS extension of the bosonic Konstein--Vasiliev model with gauge algebra hu (2^(n-1),0).

slides Sezgin_Slides.pdf

10:30 AM Coffee break

Rob Leigh: "The Exact RG and Holographic Higher Spin Theories"

slides Leigh.pdf

Murat Gunaydin: "Quasiconformal Approach to Higher Spin Algebras, their Deformation and Supersymmetric Extensions”

The standard bosonic higher spin algebra in d dimensional anti-deSitter space AdS_d is given by the enveloping algebra of SO(d-1,2) quotiented by its Joseph ideal which defines its minimal unitary representation (minrep). The quasiconformal method provides us with a unified approach to minreps of non-compact groups and leads to realizations for which the Joseph ideal vanishes identically as operators. Hence the quasiconformal realization of the enveloping algebra of the minrep of SO(d-1,2) yields directly the bosonic higher spin algebra in AdS_d. There exists a one-to-one correspondence between the minrep of SO(d-1,2) and its deformations and massless conformal fields in d-dimensional Minkowski spacetimes. The enveloping algebras of the deformed minreps lead to novel deformed higher spin algebras in AdS_d. Furthermore, the quasiconformal approach allows one to define supersymmetric extensions of higher spin algebras and their deformations. I will review the quasiconformal approach to the unitary realizations and classification of higher spin algebras , their deformations and supersymmetric extensions in all dimensions.

slides Gunaydin_MIAPP_2016.pdf

12:30 PM Lunch

Simone Giombi: "Anomalous dimensions in CFT with weakly broken higher spin symmetry"

slides Giombi.pdf

Massimo Taronna: "Cubic interactions in higher-spin theory from CFT"

Employing the conjectured duality between higher-spin theories in AdS and free CFTs, we present the complete holographically reconstructed cubic action of the minimal higher-spin theory in any dimension. The action we find is the unique solution one would obtain from solving the Noether procedure up to the quartic order.

Charlotte Sleight: "Quartic interactions in higher-spin theory from CFT"

Employing the conjectured duality between higher-spin theories on AdS and free CFTs, we extract the quartic self-interaction of the bulk scalar from the conformal block expansion of the dual CFT correlator. To this end, we demonstrate techniques to establish conformal partial wave expansions of four-point Witten diagrams. Implications for the (non-)locality of the quartic interaction are briefly discussed.

4:00 PM Coffee break

Misha Vasiliev: Current Interactions, Locality and Holography of Nonlinear Higher-Spin Equations

In this talk we derive a field redefinition that brings current
interactions in the zero-form sector of the nonlinear HS equations
in $AdS_4$ to the standard local form. It is demonstrated that the
cubic vertex resulting from the nonlinear higher-spin interactions
is independent of the free phase parameter in the system. Proper
holographic dependence on the the phase parameter is shown to
result from the phase-dependent boundary conditions.

slides Vasiliev_Slides.pdf