Scientists at Brown University have proposed a topological explanation for why the cosmological constant remains small despite predictions from quantum field theory. The study connects quantum gravity to the quantum Hall effect. It was published recently in Physical Review Letters.
Researchers Stephon Alexander, Aaron Hui and Heliudson Bernardo argue that space-time topology stabilizes the cosmological constant. Their model draws on the Chern-Simons-Kodama state and shows how topological features can suppress large quantum fluctuations.
Alexander said the topology renders disruptive quantum effects inert and keeps the constant's value stable. The approach revives a conservative method of quantizing gravity first explored by physicists such as Dirac and Wheeler.
The cosmological constant was introduced by Albert Einstein and later called his biggest blunder. Observations in 1998 confirmed the universe's accelerating expansion, restoring its importance. The new work offers one route to reconciling theory with measured values.
Further calculations are required to test the idea fully. The authors say the findings also strengthen the case for the Chern-Simons-Kodama state as a candidate for quantum gravity.