Hubble sinks in the low-redshift swampland

The cosmological standard model (ΛCDM) has recently come under pressure from measurements of the Hubble constant H₀, and theoretically from the swampland conjecture that emphasizes consistency with quantum gravity. The authors sweep through the typical class of string theory motivated dark-energy models, (coupled) quintessence with a clever expansion in low redshift and show that these models worsen the H₀ tension, but they also point to a gateway that might be tested with future 21c00exm observations.