The Hubble parameter of the Local Distance Ladder from dynamical dark energy with no free parameters

Invited talk 21st Rencontres du Vietnam. The Local Distance Ladder (LDL) places tight constraints on the late-time Hubble expansion. While the existence of dark energy is well established, its origin remains elusive. Recent observational hints of a dynamical dark energy component—if confirmed—could help resolve longstanding tensions between LDL measurements and early-Universe observations from the Planck CMB. In this work, we investigate dark energy from first principles, motivated by the anomalous scaling dimension 2 of cosmological phase space rooted in black hole physics. This framework naturally introduces a dynamical dark energy term, Λ = J, where J is the trace of the Schouten tensor, yielding an effective relation ΩΛ = (1 − q)/3 in terms of the deceleration parameter q. Using a closed-form expression for H(z), we show that this model fits the LDL-derived value of H0—consistent with Riess et al. (2022)—while maintaining a matter density aligned with BAO-inferred values in the Planck ΛCDM framework. These findings support the possibility that dark energy may have a geometric origin, potentially involving higher-order cosmographic quantities beyond q.