Cosmological constant from quantum spacetime

Shahn Majid, Wen-Qing Tao
2015 Physical Review D  
We show that a hypothesis that spacetime is quantum with coordinate algebra ½x i ; t ¼ λ P x i , and spherical symmetry under rotations of the x i , essentially requires in the classical limit that the spacetime metric is the Bertotti-Robinson metric, i.e., a solution of Einstein's equations with a cosmological constant and a non-null electromagnetic field. Our arguments do not give the value of the cosmological constant or the Maxwell field strength, but they cannot both be zero. We also
more » ... zero. We also describe the quantum geometry and the full moduli space of metrics that can emerge as classical limits from this algebra.
doi:10.1103/physrevd.91.124028 fatcat:f7x6rzie4va7ploefgadf7mthu