Advanced Lectures on Quantum Field Theory: NRGR - The PN-EFT for Compact Binaries

27 Jan 2026, 13:00 → 28 Jan 2026, 15:00 Asia/Shanghai

1502 (四牌楼校区逸夫建筑馆丘成桐中心)

Gabriel Luz Almeida (Shing-Tung Yau center, Southeast University)

The detection of gravitational waves from coalescing compact binaries by the LIGO and Virgo interferometers has revived interest in the relativistic two-body problem. These observations have profoundly advanced our understanding of both astrophysical and cosmological processes. In the mid-2000s, this field was significantly transformed by the recasting of binary dynamics into a systematic field-theoretical framework using Effective Field Theory (EFT) techniques.

Within this EFT framework, the inherent hierarchical scales of the problem delineate distinct dynamical regions. The short-distance scale governs the conservative orbital interaction via potential modes (the near zone), while the long-distance scale describes the emission and propagation of gravitational radiation (the far or radiation zone).

In this mini-course, I will present the general formulation of the EFT for compact binary systems. We will begin with foundational concepts in gravitational wave theory and EFT construction, before applying this methodology to gravitationally bound systems. The core of the lectures will focus on Non-Relativistic General Relativity (NRGR), the specific EFT that provides a rigorous power-counting framework for the post-Newtonian approximation in binary dynamics.

Tuesday 27 January

13:00 → 13:50 Lecture 1: A brief introduction to GWs and EFTs

This lecture will cover two foundational topics: the basics of gravitational waves, from linearized theory to the waveforms of coalescing binaries; and the core principles of Effective Field Theory construction using the Wilsonian approach to renormalization and the method of regions.

Convener: Gabriel Luz Almeida (Shing-Tung Yau center, Southeast University)

14:00 → 14:50 Lecture 2: The EFT for compact binary systems

This lecture will introduce the multi-scale structure of the two-body problem in GR and its formulation as an EFT. We will define the dynamical regions and introduce NRGR as the EFT framework that systematically separates these scales.

Convener: Gabriel Luz Almeida (Shing-Tung Yau center, Southeast University)

Wednesday 28 January

13:00 → 13:50 Lecture 3: The far (or radiation) zone

This lecture covers the far zone, the crucial matching procedure, and the computation of observables—including the energy-momentum tensor and the radiated energy flux—highlighting the use of the optical theorem, connecting self-energy diagrams to emission amplitudes.

Convener: Gabriel Luz Almeida (Shing-Tung Yau center, Southeast University)

14:00 → 14:50 Lecture 4: Radiative processes

We conclude the course by examining subtle, non-linear effects in gravitational-wave propagation—the tail and tails-of-tails phenomena. The lecture will demonstrate how the EFT's renormalization procedure for multipole moments provides a unified treatment of the resulting infrared and ultraviolet divergences.

Convener: Gabriel Luz Almeida (Shing-Tung Yau center, Southeast University)