Title: Combinatorial Action in Causal Set Quantum Gravity
| Speaker: | Arad Nasiri |
| Affiliation: | Imperial College London and Perimeter Institute |
| Location: | MC 5479 |
There will be a pre-seminar presenting relevant background at the beginning graduate level starting at 1pm.
Abstract: In this talk, I will first provide a brief overview of causal set theory, an approach to quantum gravity. This theory proposes that spacetime is fundamentally characterized by a partially ordered set (poset), in which the partial order represents causal relations and the number of elements signifies the volume of a spacetime manifold region. I will then discuss how efforts to find a discrete counterpart of the d'Alembertian operator on a poset led to the formulation of the causal set action S_BDG. This action is defined as a linear combination of the counts of various order intervals. Further analysis has shown that while KR posets are predominant in the number of posets of size n, the quantum dynamics imposed by S_BDG suppresses them for large n. Finally, I will propose a method to derive the combinatorial analogue of Einstein's field equations on posets.