Continuum limit and recovery of low‑energy gravity in discrete approaches

Construct the continuum limit of discrete quantum gravity approaches such as causal set theory and causal dynamical triangulations, and demonstrate recovery of low‑energy physics including graviton excitations and gravitational‑wave propagation.

Background

The third panel discussed whether spacetime is fundamental or emergent and the status of discrete approaches. A key difficulty is connecting discrete formulations to continuum physics and recovering standard low‑energy gravitational degrees of freedom.

Specific concerns included recovering gravitons and gravitational‑wave propagation and, more generally, achieving a controlled continuum limit in causal set theory and related frameworks.