Speaker
Description
The pseudo-complex version of the Friedmann–Lemaître–Robertson–Walker model (pcFLRW) is presented within the framework of pseudo-complex General Relativity (pcGR). In this approach, dark energy emerges as a geometric consequence of the pseudo-complex structure, leading to a specific functional form for the Hubble parameter H(z) characterized by a single geometric parameter beta. This parameter governs the effective dark-energy equation of state via p_Lambda = -beta times epsilon_Lambda and is directly linked to the present-day time derivative of the Hubble parameter through H-dot_0 = (3/2) times (beta minus 1) times H_0 squared. Using recent DESI BAO data, we constrain beta = 1.0426 plus or minus 0.0144, which yields a positive H-dot_0 approximately equal to (0.94 plus or minus 0.32) times 10 to the minus 17 (km/s^2)/Mpc. This contrasts with the Lambda-CDM prediction, where H-dot_0 is negative (H-dot_0 approximately equal to -0.45 times H_0 squared for standard parameters), indicating that in pcGR the expansion rate is increasing with time while in Lambda-CDM it decreases. The best-fit value also implies a deceleration parameter q = -0.9361 plus or minus 0.0216. Using the exact Sandage–Loeb relation, the predicted redshift drift over 20 years for a source at z = 4 is Delta v approximately equal to -11.1 cm per second, in close agreement with the Lambda-CDM prediction but arising from a distinct geometric origin. Thus, the non-vanishing and positive H-dot_0 in pcGR provides a clear and testable target for future high-precision spectroscopic observations.