activity
20242026
collaborators

6 papers

hep-th2026

de Sitter Wavefunction from Quadrangular Polylogarithms: Chain Graphs

Livia Ferro, Tomasz Lukowski, Lecheng Ren +4

We present an explicit formula for the -site chain graph contribution to the cosmological wavefunction for conformally coupled theory in de Sitter space. Our result relie…

hep-th2026

Landau Analysis of One-Cycle Negative Geometries

Shruti Paranjape, Marcos Skowronek, Marcus Spradlin +2

We use geometric Landau analysis to determine the singularity structure of four-point, one-cycle negative geometries in super-Yang-Mills theory, which represent cer…

hep-th2026

Symbol Alphabets in QCD and Flag Cluster Algebras

Andrzej Pokraka, Marcus Spradlin, Anastasia Volovich +1

The full 245-letter symbol alphabet for all planar massless two-loop six-point Feynman integrals was recently determined in arXiv:2412.19884 and arXiv:2501.01847. In a parallel mat…

hep-th2026

Cluster Bootstrap for Cosmological Correlators

Shruti Paranjape, Marcos Skowronek, Marcus Spradlin +2

We show that cosmological wavefunction coefficients associated with -site chain and loop graphs for a cubic scalar theory in de Sitter spacetime have symbol alphabets given by s…

hep-th2025

Split-Helicity Tree Amplitudes and Flag Cluster Algebras

Shruti Paranjape, Marcus Spradlin, Anastasia Volovich +1

Recent work has uncovered a connection between the symbol letters of general massless scattering and (permutations of) cluster variables of partial flag varieties. In this paper we…

hep-th2024

On Unitarity of Bespoke Amplitudes

Rishabh Bhardwaj, Marcus Spradlin, Anastasia Volovich +1

We use partial wave unitarity to constrain various bespoke four-point amplitudes. We start by constructing bespoke generalizations of the type I superstring amplitude, which we sho…