We present an alternative to Topologically Massive Gravity (TMG) with the same "minimal" bulk properties; i.e. a single local degree of freedom that is realized as a massive graviton in linearization about an anti-de Sitter (AdS) vacuum. However, in contrast to TMG, the new "minimal massive gravity" has both a positive energy graviton and positive central charges for the asymptotic AdS-boundary conformal algebra.
Three-dimensional Einstein gravity with negative cosmological constant admits
stationary black holes that are not necessarily spherically symmetric. We
propose boundary conditions for the near horizon region of these black holes
that lead to a surprisingly simple near horizon symmetry algebra consisting of
two affine u(1) current algebras. The symmetry algebra is essentially
equivalent to the Heisenberg algebra. The associated charges give a specific
example of "soft hair" on the horizon, as defined by Hawking, Perry and
Strominger. We show that soft hair does not contribute to the
Bekenstein-Hawking entropy of Banados-Teitelboim-Zanelli black holes and "black
flower" generalizations. From the near horizon perspective the conformal
generators at asymptotic infinity appear as composite operators, which we
interpret in the spirit of black hole complementarity. Another remarkable
feature of our boundary conditions is that they are singled out by requiring
that the whole spectrum is compatible with regularity at the horizon,
regardless the value of the global charges like mass or angular momentum.
Finally, we address black hole microstates and generalizations to cosmological
horizons.Comment: 6p
We discuss some aspects of soft hairy black holes and a new kind of "soft
hairy cosmologies", including a detailed derivation of the metric formulation,
results on flat space, and novel observations concerning the entropy.
Remarkably, like in the case with negative cosmological constant, we find that
the asymptotic symmetries for locally flat spacetimes with a horizon are
governed by infinite copies of the Heisenberg algebra that generate soft hair
descendants. It is also shown that the generators of the three-dimensional
Bondi-Metzner-Sachs algebra arise from composite operators of the affine u(1)
currents through a twisted Sugawara-like construction. We then discuss entropy
macroscopically, thermodynamically and microscopically and discover that a
microscopic formula derived recently for boundary conditions associated to the
Korteweg-de Vries hierarchy fits perfectly our results for entropy and ground
state energy. We conclude with a comparison to related approaches.Comment: 22 pp, v2: added ref
A wide class of three-dimensional gravity models can be put into "Chern-Simons-like" form. We perform a Hamiltonian analysis of the general model and then specialise to Einstein-Cartan Gravity, General Massive Gravity, the recently proposed Zwei-Dreibein Gravity and a further parity-violating generalisation combining the latter two.
Abstract. We consider the most general asymptotically flat boundary conditions in three-dimensional Einstein gravity in the sense that we allow for the maximal number of independent free functions in the metric, leading to six towers of boundary charges and six associated chemical potentials. We find as associated asymptotic symmetry algebra an isl(2) k current algebra. Restricting the charges and chemical potentials in various ways recovers previous cases, such as bms 3 , Heisenberg or Detournay-Riegler, all of which can be obtained as contractions of corresponding AdS 3 constructions. Finally, we show that a flat space contraction can induce an additional Carrollian contraction. As examples we provide two novel sets of boundary conditions for Carroll gravity.
We present a generally covariant and parity-invariant two-frame field ("zwei-dreibein") action for gravity in three space-time dimensions that propagates two massive spin-2 modes, unitarily, and we use Hamiltonian methods to confirm the absence of unphysical degrees of freedom. We show how zwei-dreibein gravity unifies previous "3D massive gravity" models and extends them, in the context of the AdS/CFT correspondence, to allow for a positive central charge consistent with bulk unitarity.
We calculate holographically arbitrary n-point correlators of the boundary stress tensor in threedimensional Einstein gravity with negative or vanishing cosmological constant. We provide explicit expressions up to 5-point (connected) correlators and show consistency with the Galilean conformal field theory Ward identities and recursion relations of correlators, which we derive. This provides a novel check of flat space holography in three dimensions.
Abstract:We consider two possible flat space limits of three dimensional N = (1, 1) AdS supergravity. They differ by how the supercharges are scaled with the AdS radius ℓ: the first limit (democratic) leads to the usual super-Poincaré theory, while a novel 'twisted' theory of supergravity stems from the second (despotic) limit. We then propose boundary conditions such that the asymptotic symmetry algebras at null infinity correspond to supersymmetric extensions of the BMS algebras previously derived in connection to non-and ultra-relativistic limits of the N = (1, 1) Virasoro algebra in two dimensions. Finally, we study the supersymmetric energy bounds and find the explicit form of the asymptotic and global Killing spinors of supersymmetric solutions in both flat space supergravity theories.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.