Twistor-Strings, Grassmannians and Leading Singularities by Bullimore, M, Mason, L, Skinner, D

“…We go on to show that the genus g twistor-string moduli space for g-loop N^{k-2}MHV amplitudes may be mapped into the Grassmannian G(k,n). Restricting to a leading singularity, the image of this map is a 2(n-2)-dimensional subcycle of G(k,n) of exactly the type found from the Grassmannian residue formula of Arkani-Hamed, Cachazo, Cheung and Kaplan. …”

Twistor-strings, Grassmannians and leading singularities by Bullimore, M, Mason, L, Skinner, D

Gravity in Twistor Space and its Grassmannian Formulation by Cachazo, F, Mason, L, Skinner, D

“…In addition, we provide a description of gravity amplitudes as a multidimensional contour integral over a Grassmannian. The Grassmannian formulation has a very simple structure; in the N$^{k-2}$MHV sector the integrand is essentially the product of that of an MHV and an $\overline{{\rm MHV}}$ amplitude, with $k+1$ and $n-k-1$ particles respectively.…”

Dual Superconformal Invariance, Momentum Twistors and Grassmannians by Mason, L, Skinner, D

“…We show that tree amplitudes and box coefficients are succinctly generated by integration of holomorphic delta-functions in momentum twistors over cycles in a Grassmannian. This is analogous to, although distinct from, recent results obtained by Arkani-Hamed et al. in ordinary twistor space. …”

Combinatorial aspects of scattering amplitudes: amplituhedra, T-duality, and cluster algebras by Parisi, M

Subjects: “…Scattering Amplitudes, N=4 Super Yang-Mills Theory, On-shell Methods, Grassmannians, Amplituhedron, Positive Geometries, Algebraic Combinatorics, Combinatorial Algebraic Geometry, Matroid and Positroid Theory, Tropical Geometry, and Cluster Algebras.…”

THE LANDAU-LIFSHITZ EQUATION, ELLIPTIC-CURVES AND THE WARD TRANSFORM by Carey, A, Hannabuss, K, Mason, L, Singer, M

“…An appendix is devoted to a careful definition of the Grassmannian of the Frechet space C∞(S1). © 1993 Springer-Verlag.…”

Tau functions and the twistor theory of integrable systems by Mason, L, Singer, M, Woodhouse, N

“…We first define τ-functions as generalized cross-ratios of four points on a finite- or infinite-dimensional Grassmannian. We show how this definition can be used to construct a natural flat connection on a determinant line bundle associated with two equivariant holomorphic vector bundles over a twistor space, provided that the action of the symmetries on the bundles has the same normal form at the fixed points for the two bundles. …”

The correlahedron by Eden, B, Heslop, P, Mason, L

“…Re-expressing the Grassmann dependence of correlation functions of n chiral stress-energy multiplets with Grassmann degree 4k in terms of 4(n + k)-linear bosonic variables, the resulting expressions have an interpretation as volume forms on a Gr(n+k, 4+n+k) Grassmannian, analogous to the expressions for planar amplitudes via the amplituhedron. …”

Scattering Amplitudes and Wilson Loops in Twistor Space by Adamo, T, Bullimore, M, Mason, L, Skinner, D

“…We give a brief review of other ideas in connection with amplitudes in twistor space: twistor-strings, recursion in twistor space, the Grassmannian residue formula for leading singularities and amplitudes as polytopes. …”