arXiv subjects

Nemani V. Suryanarayana

Publications and source records attributed to Nemani V. Suryanarayana.

At least 19 recordsLinked to original sources

arXiv2026

Towards celestial CFT dual of 4d conformal gravity

We compute tree-level celestial operator product expansions (OPE) in a bosonic sub-sector of the Berkovits-Witten conformal supergravity from the scattering amplitudes in the MHV configuration. While the OPE between a leading soft graviton current for a positive helicity graviton and any of the primary operators exhibits the same singularity structure as in a gravitational theory with two-derivative kinetic terms, the OPE of a subleading soft graviton current with a positive helicity hard graviton primary operator receives corrections, as a consequence of the non-universal nature of the subleading soft graviton theorem in the bulk. Remarkably, the subleading soft graviton terms remain consistent with the Ward identity of the chiral $\mathfrak{sl}(2,\mathbb{R}) $ current algebra, albeit with a different realisation where particle-changing operators play a role. Our analysis suggests that the dual celestial CFT continues to enjoy at least the chiral $\mathfrak{bms}_4$ symmetry, though in a non-trivial way, and possibly a conformal extension of it.

hep-th↗

arXiv2026

Celestial dual of conformal gravity MHV amplitudes: an OPE analysis

In an earlier paper [arXiv:2511.03669] we extracted the OPE of celestial CFT operator duals of positive helicity graviton and scalar particles from the Mellin transformed relevant MHV amplitudes of conformal gravity, realised as the bosonic subsector of the Berkovits-Witten theory. A soft theorem analysis of bulk MHV amplitudes established that this conformal gravity exhibits a chiral $\mathfrak{bms}_4$ symmetry on the celestial sphere with the associated $\mathfrak{sl}(2,\mathbb{R})$ current algebra, which acquires a non-trivial central extension, unlike the Einstein gravity. Here we construct a $2d$ chiral CFT free-field realisation of the relevant chiral $\mathfrak{bms}_4$ algebra in terms of three free scalars ($ϕ_i$) and three $(β_i,γ_i)$ ghost pairs, and propose vertex operators for the positive-helicity graviton primary $G^{++}_Δ(z,\bar{z})$ as well as the scalar primary $Φ_Δ(z,\bar{z})$, and compute their OPEs. These OPEs reproduce exactly those obtained from the bulk conformal gravity MHV amplitudes, providing a concrete celestial dual description of its MHV sector.

hep-th↗

arXiv2025

Super-Giants in Gutowski-Reall Black Hole

We present all bosonic giant and dual-giant type configurations of a probe D3-brane in the BPS single-parameter Gutowski-Reall black hole in 10d type IIB supergravity that do not break any of its supersymmetries. The resulting D3-brane world-volumes can be given by the common zeros of three holomorphic functions of five complex scalar harmonics of the geometry. These probe branes support world-volume electromagnetic fields which we characterise completely in terms of pull-backs of closed 2-forms. Our configurations can be seen as natural generalisations of known supersymmetric D3-branes in $AdS_5 \times S^5$ and approach them far away from the black hole horizon.

hep-th↗

arXiv2025

Chiral $Λ$-$\mathfrak{bms}_4$ symmetry of 3d conformal gravity

We propose mixed boundary conditions for 3d conformal gravity consistent with variational principle in its second-order formalism that admit the chiral $Λ$-$\mathfrak{bms}_4$ algebra as their asymptotic symmetry algebra. This algebra is one of the four chiral $\mathcal W$-algebra extensions of $\mathfrak{so}(2,3)$ and is a generalisation of the chiral $\mathfrak{bms}_4$ algebra responsible for soft theorems of graviton MHV amplitudes in ${\mathbb R}^{1,3}$ gravity to the case of non-zero negative cosmological constant. The corresponding charges calculated using the modified covariant phase space formalism are shown to be finite and integrable, and realise this non-linear ${\cal W}$-algebra.

hep-th↗

arXiv2024

A Chiral $Λ$-$\mathfrak{bms}_4$ Symmetry of AdS$_4$ Gravity

Generalising the chiral boundary conditions of $\mathbb{R}^{1,3}$ gravity for AdS$_4$ gravity, we derive chiral locally AdS$_4$ solutions in the Newman-Unti gauge consistent with a variational principle whose asymptotic symmetry algebra we show, to be an infinite-dimensional chiral extension of $\mathfrak{so}(2,3)$. This symmetry algebra coincides with the chiral $\mathfrak{bms}_4$ algebra in the flat space limit. We posit this symmetry algebra as the chiral version of recently discovered $Λ$-$\mathfrak{bms}_4$ algebra. We postulate line integral charges from the bulk AdS$_4$ gravity corresponding to this chiral symmetry algebra and show that the charges obey the semi-classical limit of a $\mathcal{W}$-algebra that includes a level $κ$ Kac-Moody $\mathfrak{sl}(2,\mathbb{R})$ current algebra. Furthermore, using the standard tools of $2d$ CFT, we derive the quantum version of this $\mathcal{W}$-algebra which may be denoted by $\mathcal{W}(2;(3/2)^2,1^3)$.

hep-th↗

arXiv2024

All chiral ${\cal W}$-algebra extensions of $\mathfrak{so}(2,3)$

We show that there are four chiral ${\cal W}$-algebra extensions of $\mathfrak{so}(2,3)$ algebra and construct them explicitly. We do this by a simple identification of each of the inequivalent embeddings of a copy of $\mathfrak{sl}(2,{\mathbb R})$ in the $\mathfrak{so}(2,3)$ algebra and the maximal subalgebra $\mathfrak{h}$ that commutes with it. Then using the standard 2d chiral CFT techniques we find the corresponding ${\cal W}$-algebra extensions. Two of the four resultant ${\cal W}$-algebras are new, one of which may be thought of as the conformal $\mathfrak{bms}_3$ algebra valid for finite values of its central charge.}

hep-th↗

arXiv2023

$\widehat{sl_2}$ symmetry of ${\mathbb R}^{1,3}$ gravity

We propose novel asymptotically locally flat boundary conditions for Einstein Gravity without cosmological constant in four dimensions that are consistent with the variational principle. They allow for complex solutions that are asymptotically diffeomorphic to flat space-times under complexified diffeomorphisms. We show that the resultant asymptotic symmetries are an extension of the Poincare algebra to a copy of Virasoro, a chiral $\mathfrak{sl}(2,{\mathbb C})$ current algebra along with two chiral $\mathfrak{u}(1)$ currents. We posit that these bulk symmetries are direct analogues of the recently discovered chiral algebra symmetries of gravitational scattering amplitudes as celestial CFT correlation functions.

hep-th↗

arXiv2020

On BPS Strings in ${\mathcal N}=4$ Yang-Mills Theory

We study singular time-dependent $\frac{1}{8}$-BPS configurations in the abelian sector of ${{\mathcal N}= 4}$ supersymmetric Yang-Mills theory that represent BPS string-like defects in ${{\mathbb R}\times S^3}$ spacetime. Such BPS strings can be described as intersections of the zeros of holomorphic functions in two complex variables with a 3-sphere. We argue that these BPS strings map to $\frac{1}{8}$-BPS surface operators under the state-operator correspondence of the CFT. We show that the string defects are holographically dual to noncompact probe D3-branes in global $AdS_5\times S^5$ that share supersymmetries with a class of dual-giant gravitons. For simple configurations, we demonstrate how to define a good variational problem and propose a regularization scheme that leads to finite energy and global charges on both sides of the holographic correspondence.

hep-th↗

arXiv2020

Constructing Carrollian CFTs

We construct classical theories for scalar fields in arbitrary Carroll spacetimes that are invariant under Carrollian diffeomorphisms and Weyl transformations. When the local symmetries are gauge fixed these theories become Carrollian conformal field theories. We show that generically there are at least two types of such theories: one in which only time derivatives of the fields appear and the other in which both space and time derivatives appear. A classification of such scalar field theories in three (and higher) dimensions up to two derivative order is provided. We show that only a special case of our theories arises in the ultra-relativistic limit of a covariant parent theory.

hep-th↗

arXiv2018

On Asymptotic Symmetries of 3d Extended Supergravities

We study asymptotic symmetry algebras for classes of three dimensional supergravities with and without cosmological constant. In the first part we generalise some of the non-Dirichlet boundary conditions of $AdS_3$ gravity to extended supergravity theories, and compute their asymptotic symmetries. In particular, we show that the boundary conditions proposed to holographically describe the chiral induced gravity and Liouville gravity do admit extension to the supergravity contexts with appropriate superalgebras as their asymptotic symmetry algebras. In the second part we consider generalisation of the 3d $BMS$ computation to extended supergravities without cosmological constant, and show that their asymptotic symmetry algebras provide examples of nonlinear extended superalgebras containing the $BMS_3$ algebra.

hep-th↗

arXiv2018

Scalar Blocks as Gravitational Wilson Networks

In this paper we continue to develop further our prescription [arXiv:1602.02962] to holographically compute the conformal partial waves of CFT correlation functions using the gravitational open Wilson network operators in the bulk. In particular, we demonstrate how to implement it to compute four-point scalar partial waves in general dimension. In the process we introduce the concept of OPE modules, that helps us simplify the computations. Our result for scalar partial waves is naturally given in terms of the Gegenbauer polynomials. We also provide a simpler proof of a previously known recursion relation for the even dimensional CFT partial waves, which naturally leads us to an odd dimensional counterpart.

hep-th↗

arXiv2016

Holographic Conformal Partial Waves as Gravitational Open Wilson Networks

We propose a method to holographically compute the conformal partial waves in any decomposition of correlation functions of primary operators in conformal field theories using open Wilson network operators in the holographic gravitational dual. The Wilson operators are the gravitational ones where gravity is written as a gauge theory in the first order Hilbert-Palatini formalism. We apply this method to compute the global conformal blocks and partial waves in 2d CFTs reproducing many of the known results.

hep-th↗

arXiv2014

Holographic chiral induced W-gravities

We study boundary conditions for 3-dimensional higher spin gravity that admit asymptotic symmetry algebras expected of 2-dimensional induced higher spin theories in the light cone gauge. For the higher spin theory based on sl(3, R) plus sl(3,R) algebra, our boundary conditions give rise to one copy of classical W3 and a copy of sl(3,R) or su(1,2) Kac-Moody symmetry algebra. We propose that the higher spin theories with these boundary conditions describe appropriate chiral induced W-gravity theories on the boundary. We also consider boundary conditions of spin-3 higher spin gravity that admit u(1) plus u(1) current algebra.

hep-th↗

arXiv2013

An sl(2, R) current algebra from AdS_3 gravity

We provide a set of chiral boundary conditions for three-dimensional gravity that allow for asymptotic symmetries identical to those of two-dimensional induced gravity in light-cone gauge considered by Polyakov. These are the most general boundary conditions consistent with the boundary terms introduced by Compere, Song and Strominger recently. We show that the asymptotic symmetry algebra of our boundary conditions is an sl(2,R) current algebra with level given by c/6. The fully non-linear solution in Fefferman--Graham coordinates is also provided along with its charges.

hep-th↗

arXiv2012

Counterterms, critical gravity and holography

We consider counterterms for odd dimensional holographic CFTs. These counterterms are derived by demanding cut-off independence of the CFT partition function on $S^d$ and $S^1 \times S^{d-1}$. The same choice of counterterms leads to a cut-off independent Schwarzschild black hole entropy. When treated as independent actions, these counterterm actions resemble critical theories of gravity, i.e., higher curvature gravity theories where the additional massive spin-2 modes become massless. Equivalently, in the context of AdS/CFT, these are theories where at least one of the central charges associated with the trace anomaly vanishes. Connections between these theories and logarithmic CFTs are discussed. For a specific choice of parameters, the theories arising from counterterms are non-dynamical and resemble a DBI generalization of gravity. For even dimensional CFTs, analogous counterterms cancel log-independent cut-off dependence.

hep-th↗

arXiv2010

Supersymmetric Electromagnetic Waves on Giants and Dual-Giants

We set up the BPS equations for a D3-brane moving in AdS_5 \times S^5 which preserves two supercharges and with all bosonic fields turned on in the world-volume theory. By solving these, we find generalizations of Mikhailov giants and wobbling dual-giants that include electromagnetic waves propagating on their world-volume. For these giants (dual-giants) we show that the BPS field strength is the real part of the pull-back of a holomorphic 2-form in the ambient space C^3 (C^{1,2}) onto the world-volume.

hep-th↗

arXiv2008

Counting Wobbling Dual-Giants

We derive the BPS equations for D3-branes embedded in AdS_5 X S^5 that preserve at least two supercharges. These are given in terms of conditions on the pullbacks of some space-time differential four-forms. Solutions to our equations are shown to describe all the known giant and dual-giant gravitons in AdS_5 X S^5. We then argue that the configuration spaces of dual-giants can be mapped to non-compact hyperbolic versions of complex projective spaces, in contrast with the giants, whose configuration spaces have been mapped to complex projective spaces. We quantize the configuration space of the 1/8-BPS dual-giants with two angular momenta in AdS_5 and one angular momentum in S^5 and find agreement with the partition function in the literature obtained both from counting appropriate 1/8-BPS configurations of giants and the boundary gauge theory considerations.

hep-th↗

arXiv2007

Charges from Attractors

We describe how to recover the quantum numbers of extremal black holes from their near horizon geometries. This is achieved by constructing the gravitational Noether-Wald charges which can be used for non-extremal black holes as well. These charges are shown to be equivalent to the U(1) charges of appropriately dimensionally reduced solutions. Explicit derivations are provided for 10 dimensional type IIB supergravity and 5 dimensional minimal gauged supergravity, with illustrative examples for various black hole solutions. We also discuss how to derive the thermodynamic quantities and their relations explicitly in the extremal limit, from the point of view of the near-horizon geometry. We relate our results to the entropy function formalism.

hep-th↗