[Seminar] "Constraining Quantum Gravity from the Bottom-up" by Dr. Scott Melville

Quantum Gravity Unit (Neiman Unit) would like to invite you to a seminar by Dr. Scott Melville from Imperial College London

Title: "Constraining Quantum Gravity from the Bottom-up"

Abstract:

Gravity on large scales is relatively well understood. For galaxies, planets and apples: we have Einstein’s General Relativity with which to make accurate predictions. But on small scales, where quantum mechanics becomes important, gravity is more difficult to understand, and as a result we lack precise descriptions of various natural phenomena (such as black holes).

One way to make progress in in our search for quantum gravity is to start from the large scale theory we know and love (at the ‘bottom’), and look for ways in which it may be modified and improved as we zoom in to smaller scales (going ‘up’ to a more fundamental theory).

Recent progress in ‘Effective Field Theory’ may shed some light on the connections between large and small scale physics. By exploiting certain physical properties of scattering probabilities (e.g. that they are unitary, causal and local), one can derive an infinite number of constraints which any large scale theory must satisfy in order to admit a sensible small scale completion.

In this talk, I will provide an overview of these new ‘positivity constraints’, and discuss their implications for quantum gravity.