SEMINAR:End of time in field theories

Guest: Fethi M. Ramazanoğlu, Koç University

Title: End of time in field theories (PHYS, MATH)

Date/Time: November 13, 2024, 13:40

Location: FENS L029

Abstract: The concept of time essentially says that we can know the future if we are given the state of a system right now. Hence, time is an essential part of our understanding of nature, and its existence is usually taken as granted in a mathematical formulation of a theory if we follow some simple guidelines. We will refute this idea in this talk, demonstrating that some of the simplest theories one can write down, such as self-interacting vector field theories, do not have indefinite time evolution. Namely, time evolution exists for a finite duration, but dynamics becomes impossible afterwards. We will discuss how this bizarre occurrence can be used to rule out many proposals in physics, helping us constrain the landscape of alternative theories in gravity and beyond. This is especially valuable in an era of abundance in alternative theoretical ideas and a relative scarcity of experiments and observations to constrain them.

Reference: 10.1103/PhysRevLett.129.151103, 10.1103/PhysRevLett.130.021401

Bio: Fethi Mübin Ramazanoğlu completed his BS degree at Massachusetts Institute of Technology and PhD at Princeton University. After postdoctoral positions at Princeton and the University of Cambridge, he joined Koç University Physics Department in 2016 where he is currently an Associate Professor. He mainly works on gravitational physics with a special interest in numerical relativity and alternative theories of gravity.