Physics Colloquium - Zvi Bern

Physics Colloquium - Zvi Bern

101 Osmond and https://psu.zoom.us/j/93946951319?pwd=dFVHR21XbDExR0JQanNBUldENEFvQT09

2023-03-30

Title: From Quantum Scattering Amplitudes to Gravitational Waves

Abstract: The remarkable detection of gravitational waves by the LIGO/Virgo collaboration has opened a new window into the cosmos. In this colloquium we explain how particle theorists can help out with calculations directly relevant for gravitational-wave emission from compact astrophysical objects. The past decade has seen enormous advances in our ability to compute quantum scattering amplitudes making seemingly impossible calculations tractable. These advances include ideas such as the duality between color and kinematics, double-copy relations, generalized unitarity, and improved integration methods. The starting point in this approach is that gravity is transmitted by a massless spin 2 particle. After introducing these concepts, we explain how these ideas are transferred to produce new state-of-the-art calculations for the astrophysical binary black hole inspiral problem.

Schedule for Physics Colloquium - Zvi Bern
Time	Speaker	Title
15:45	Zvi Bern	From Quantum Scattering Amplitudes to Gravitational Waves

The IGC wordmark was created by Monica Rincon Ramirez, while she was a graduate student at the Institute for Gravitation and the Cosmos (IGC). Monica enjoys drawing new connections between fundamental theory and observations. Her graduate work includes specialized topics in general relativity, loop quantum gravity, and quantum fields in cosmological backgrounds. In particular, her thesis work focused on finding effective quantum corrections to gravitational phenomena from spinfoams, and applications to cosmology. She received her PhD in 2024.

The wordmark symbolizes the scope and variety of research at the IGC. The base of the image represents quantum gravity, evoking the quantum geometrical picture from spinfoams and loop quantum gravity. These are among the approaches to fundamental questions studied at the Center for Fundamental Theory. The middle of the image represents the Center for Theoretical and Observational Cosmology by galaxies embedded in a smooth surface, characteristic of spacetime in general relativity and the much larger physical scales studied in cosmology. Finally, at the top, the surface curves to an extreme, representing a supermassive black hole accompanied by an energetic jet. These elements depict an active galactic nucleus, inspired by Centaurus A. Just to the right, a pair of black holes approaches merger. This top portion of the wordmark represents the Center for Multimessenger Astrophysics, which specializes in the study of high-energy phenomena in the universe.