Sudarshan Ananth

KLT relations from the Einstein-Hilbert Lagrangian

The Kawai–Lewellen–Tye (KLT) relations derived from string theory tell us that perturbative gravity amplitudes are the “square” of the corresponding amplitudes in gauge theory. Starting from the light-cone Lagrangian for pure gravity we make these relations manifest off-shell, for three- and four-graviton vertices, at the level of the action.

Proof of all-order finiteness for planar beta-deformed Yang-Mills

We study a marginal deformation of N = 4 Yang–Mills, with a real deformation parameter β. This β-deformed model has only N = 1 supersymmetry and a U(1)×U(1) flavor symmetry. The introduction of a new superspace ⋆-product allows us to formulate the theory in N = 4 light-cone superspace, despite the fact that it has only N = 1 supersymmetry. We show that this deformed theory is conformally invariant, in the planar approximation, by proving that its Green functions are ultra-violet finite to all orders in perturbation theory.

Proof of ultra-violet finiteness for a planar non-supersymmetric Yang-Mills theory

Abstract This paper focuses on a three-parameter deformation of N = 4 Yang–Mills that breaks all the supersymmetry in the theory. We show that the resulting non-supersymmetric gauge theory is scale invariant, in the planar approximation, by proving that its Green functions are ultraviolet finite to all orders in light-cone perturbation theory.

The N=8 supergravity Hamiltonian as a quadratic form

Abstract We conjecture that the light-cone Hamiltonian of N = 8 supergravity can be expressed as a quadratic form. We explain why this rewriting is unique to maximally supersymmetric theories. The N = 8 quartic interaction vertex is constructed and used to verify that this conjecture holds to order κ 2 .

Spinor helicity structures in higher spin theories

A bstractIt is shown that the coefficient of the cubic interaction vertex, in higher spin Lagrangians, has a very simple form when written in terms of spinor helicity products. The result for a higher-spin field, of spin λ, is equal to the corresponding Yang-Mills coefficient raised to the power λ. Among other things, this suggests perturbative ties, similar to the KLT relations, between higher spin theories and pure Yang-Mills. This result is obtained in four-dimensional flat spacetime.

The quintic interaction vertex in light-cone gravity

Abstract We consider pure gravity in light-cone gauge and derive the complete quintic interaction vertex. Up to quartic order, the Kawai–Lewellen–Tye (KLT) relations can be made manifest at the level of the Einstein–Hilbert Lagrangian. The quintic interaction vertex represents an essential first step in further extending the off-shell validity of the KLT relations to higher order vertices.

A manifestly MHV Lagrangian for N=4 Yang-Mills

We derive a manifestly MHV Lagrangian for the

GRAVITY AND YANG–MILLS THEORY

\mathcal{N} = 4

Yang-Mills theories and quadratic forms

supersymmetric Yang-Mills theory in light-cone superspace. This is achieved by constructing a canonical redefinition which maps the

Gauge-invariant correlation functions in light-cone superspace

\mathcal{N} = 4