arXiv subjects

Aswini Bala

Publications and source records attributed to Aswini Bala.

8 recordsLinked to original sources

arXiv2026

$\mathbb{R}$eal Ambitwistors & Massive Twistors for CFT$_4$

We develop a real twistor-space formulation of four-dimensional CFT Wightman correlators. We write the conformal generators and little-group constraints in ambitwistor space. The quadric condition $Z\cdot W$=0 arises naturally from the little-group constraints. We then solve for both the parity-even and parity-odd correlators in the ambitwistor variables. We further establish the connection between the ambitwistor correlators and the ones in the helicity-basis Grassmannian via a half-Fourier transform, and also develop the Penrose transform to recover the corresponding position-space correlators. We notice that for correlators with multiple tensor structures, the Penrose transform yields the full space of conformally invariant structures, but regularizing the associated Schwinger integrals selects the physical correlator. Finally, starting from the covariant Grassmannian formulation, we construct massive twistors that make the little-group symmetries manifest and develop their Penrose transform, which again reproduces the correct position-space correlators.

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arXiv2026

A Cosmological BCFW Bridge and Its Canonical Geometry

We build a BCFW-like recursion for cosmological correlators using the orthogonal Grassmannian. The key step is a bridge deformation that leaves all the Grassmannian constraints intact. The recursion relations are purely algebraic and avoid any spectral or radial integrals that usually appear in curved space. We obtain the gluon 4-point correlator using this bridge, producing two factorization poles, a total energy singularity coming from the three point building block, and a shifted energy singularity that emerges only after adding the two channels using recursion. We then show that the helicity stripped four-gluon correlator has the canonical form of a rectangle, where its boundaries represent various poles. We also describe the geometry of the gluon correlator in the Pfaffians as the natural coordinates in the Grassmannian. Using multiple deformation bridges, we also obtain the graviton four point correlator and observe a double-copy like relation at the level of the four point function, away from the physical cuts for each channel. We also extended the BCFW bridge formalism to the supersymmetric Grassmannian.

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arXiv2026

The Conformal Grassmannian: A Symplectic Bi-Grassmannian for $CFT_ 4$ Correlators

We introduce a formalism for conformal field theory in four dimensions: a symplectic bi-Grassmannian representation of CFT$_4$ Wightman correlators. Working in Klein space with off-shell spinor-helicity variables, we show that correlators of $\Delta = 2$ scalars and symmetric-traceless conserved currents are encoded by integrals over a pair of $n$-planes in a $2n$-dimensional symplectic vector space. These planes are constrained to be mutually symplectically orthogonal and aligned with the external kinematics. Conformal invariance, momentum conservation, and little-group covariance all follow geometrically from this structure. We derive all two- and three-point functions involving scalars, fermions, conserved currents, and stress tensors. As a non-trivial test, we show that the construction reproduces the full set of independent conformally invariant structures of $\langle JJJ\rangle$ and $\langle TTT\rangle$ in CFT$_4$. The resulting expressions are considerably more compact than their momentum-space counterparts. They also make manifest the double copy between Yang--Mills $\langle JJJ \rangle$ and Einstein-gravity $\langle TTT \rangle$. We further present a helicity-basis reformulation that makes the GL(1,R) and SL(2,R) weights of individual helicity components explicit. This basis also provides a natural starting point for a twistor-space formulation of the correlators.

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arXiv2026

The $\mathcal{N}=1$ Super-Grassmannian for CFT$_3$ and a Foray on AdS and Cosmological Correlators

We construct a Super-Grassmannian integral representation for $n-$point functions in $\mathcal{N}=1$ SCFT$_3$. In this formalism, conformal invariance, supersymmetry, and special superconformal invariance are implemented manifestly through (operator-valued) delta function constraints. An important feature of this framework is the fact that we obtain simple algebraic relations among component correlators, which enable us to determine any component correlator in terms of just one of the component correlators. In particular, this formalism enables us to construct (A)dS$_4$ boundary correlators with contact diagrams from those that receive contributions purely from particle exchanges. We illustrate this by determining the (A)dS$_4$ Yang-Mills gluon four-point function from its gluino counterpart. Further, we establish the flat-space limit in super-space, finding a perfect agreement with existing flat-space results.

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arXiv2026

Super-Grassmannians for $\mathcal{N}=2$ to $4$ SCFT$_3$: From AdS$_4$ Correlators to $\mathcal{N}=4$ SYM scattering Amplitudes

We construct a Super-Grassmannian for $n-$point functions in $\mathcal{N}=2$ to $4$ SCFT$_3$. The constraints imposed by super-conformal invariance and $R-$symmetry are completely manifest in this formalism through (operator-valued) delta functions. We test our formalism in $\mathcal{N}=2$ and $\mathcal{N}=4$ AdS$_4$ super Yang-Mills theories. In the $\mathcal{N}=2$ case, for instance, we reproduce the four-gluon correlator using the four-point scalar correlator as input. For $\mathcal{N}=4$, we construct the super-operator in two distinct ways. In one approach, the super-operator has a lowest component of spin zero and includes all states up to spin two. In the other approach, we build the super-operator in a CPT self-conjugate manner, which contains only operators with spin zero, spin half, and spin one mimicking flat space $\mathcal{N}=4$ SYM super-field constructions. The latter construction is particularly interesting, as it matches directly with the $\mathcal{N}=4$ SYM amplitudes in the flat space limit, thereby demonstrating the non-triviality and usefulness of our framework. It is interesting to note that the $R-$symmetry group enhances from $SO(\mathcal{N})$ to $SU(\mathcal{N})$ in the flat space limit.

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arXiv2025

An Ode to the Penrose and Witten transforms in Twistor space for 3D CFT

Here we discuss the construction of Sp$(4;\mathbb{R})$ invariant objects in the twistor space for three dimensional conformal field theories. The Sp$(4;\mathbb{R})$ invariant projective delta function, alongside the Twistor symplectic dot product invariants form the basis for conformal Wightman functions involving conserved currents and $\Delta=1$ scalars. For correlators involving scalars with $\Delta\ne 1$, generic spinning primaries and parity odd correlators we show that the infinity twistor of $\mathbb{R}^{2,1}$ must be incorporated into the analysis. We show that this feature can be traced to the Penrose and Witten transforms of these operators that we derive. We then discuss the super-twistor space construction and derive the supersymmetric Penrose transform for $\mathcal{N}=1$ theories using the Fourier transform and the supersymmetric Witten transform. We construct OSp$(\mathcal{N}|4;\mathbb{R})$ invariants and its application to several super-Wightman functions. Similar to the non supersymmetric case, we find an important role played by the (super) infinity twistor which we exemplify through parity odd super-correlators and a supersymmetric contact term.

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arXiv2025

A Supertwistor Formalism for $\mathcal{N}=1,2,3,4\;\text{SCFT}_3$

We develop a manifest supertwistor space formalism for three dimensional $\mathcal{N}=1, 2,3,4$ superconformal field theories. This formalism simultaneously makes manifest the supersymmetry, conformal invariance and conservation. We solve two and three point correlators of (half) integer spin conserved supercurrents using the graded supergroup generators. Apart from the superconformal generators, we find that the superhelicity operators are necessary to fix their functional form in this setup. The superhelicity operators can be recast into first order Euler equations which besides the standard polynomial solutions, also admit weak solutions that are distributional in nature. They play an important role in the case of three point functions, where the super-correlator takes the form of a product of delta functions. Interestingly, we find that these super-correlators are extremely simple, elegant and uniform for all spins and for all $\mathcal{N}\leq4$, which resemble the non supersymmetric correlators where the twistors are replaced with appropriately defined supertwistors.

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arXiv2025

3D Conformal Field Theory in Twistor Space

The aim of this paper is to study three dimensional Lorentzian conformal field theories in twistor space. We formulate the conformal Ward identities and solve for two and three point Lorentzian Wightman functions. We found that the Helicity operators apart from the conformal generators play an important role in fixing their functional form. The equations take the form of first order Euler equations which in addition to the usual solutions that are polynomials, also possess weak solutions which are distributional in nature. All of these play an important role in our analysis. For instance, in the case of three point functions, the distributional solutions are indeed the ones realized by the CFT correlators. We also extend our analysis to parity odd Wightman functions which take an interesting form in twistor space. We verify our results by systematically analyzing the corresponding Wightman functions in momentum space and spinor helicity variables and matching with the twistor results via a half-Fourier transform.

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