Classical Observables in Gravity from Yang-Mills

• Grant number: 25/26975-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: February 01, 2026
• End date: April 30, 2029
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Gabriel Santos Menezes
• Grantee: Lucas Haiashi Lima
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 25/02861-0 - Scattering amplitudes in Gauge theories and gravity, AP.JP

Abstract

This research project explores the intersection between quantum field theory and general relativity, aiming to accurately compute classical observables in gravitational scattering processes. Our main focus is the dynamics of spinning binary black hole systems. We will investigate the extension of the on-shell amplitude formalism to derive the variation of the spin vector (the angular impulse) at Next-to-Leading Order (NLO).Unlike approaches restricted to the conservative regime, this project explicitly incorporates radiation reaction effects. We aim to derive analytic expressions for the angular impulse using the KMOC (Kosower-Maybee-O'Connell) formalism.Furthermore, we will investigate the systematic application of Leading Singularities to simplify the complexity of loop integrals. Our goal is to use this technique to determine amplitude coefficients relevant to the classical potential and spin observables, isolating the non-analytic parts of the gravitational scattering amplitude without the need to directly integrate spurious quantum terms.Additionally, we will investigate the universality of gravitational coupling for particles with arbitrary spin, establishing a connection between minimally coupled amplitudes and Kerr solutions. Finally, we will discuss how the color-kinematics duality (double copy) can simplify these calculations, providing robust theoretical data for gravitational wave modeling fundamental to the current and future generation of detectors. (AU)