施灿欣 博士学术报告

Title: Extracting spinning two-body observables from S-matrix

Speaker: Canxin Shi (施灿欣)

Affiliation: Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所)

Time: 16:00-17:00, Friday, November 7th, 2025 (UTC+8, Beijing Time)

Venue: Zoom Meeting (ID: 385 442 0225; Passcode: yauc)

Inviter: Zhengwen Liu (刘正文)

Abstract

High-precision prediction of the two-body problem is at the center of gravitational waves physics. I will present a novel method for extracting observables for two-body scattering systems from a set of generating functions, with full spin dependence. The approach uses the classical limit of the logarithm of the quantum S-matrix as generating functions. The 4-point matrix element of Log(S) gives the radial action, corresponding to conservative effects, whereas the higher-point contributions encode radiative information. Different observables, such as momentum impulse, orbital angular momentum, and waveform, are uniformly obtained by from the generating functions. We demonstrate its power by calculating new high-precision results, including the impulse and spin kick for a probe in Kerr up to O(G^6 s^4), and the change in angular momentum for generic masses up to O(G^2 s^11). Via analytic continuation, we can also provide information about bound orbits, such as their fundamental frequencies.

Speaker

Canxin Shi is currently a postdoc at the Institute of Theoretical Physics, Chinese Academy of Sciences.

The seminar will be broadcasted online by Zoom.

Interested people are free to join, without registration in advance.

The Zoom info is

URL: https://us02web.zoom.us/j/3854420225?pwd=SXY4eWJKOTBFZWJDaE16aXpTamY1QT09

Meeting ID: 385 442 0225

Passcode: yauc