Revisiting the Matter Creation Process: Observational Constraints on Gravitationally Induced Dark Energy and the Hubble Tension

Abstract

The Hubble tension and the unknown origin of dark energy motivate the exploration of alternative mechanisms for late-time cosmic acceleration. We investigate gravitationally induced particle creation (PC) as a non-equilibrium process that can effectively mimic dynamical dark energy. Within the thermodynamic framework of open systems, we adopt an agnostic approach to the extra created component, leaving its equation-of-state parameter $w_E$ free. We consider four phenomenological parametrisations of the PC rate, allowing deviations from the standard cosmological model ($\hat{I}›$CDM) only at late times ($0<z<3$). The PC models are constrained using a joint analysis of cosmic chronometers, Type Ia supernovae, local $H_0$ measurements, baryon acoustic oscillations, and cosmic microwave background data. The constraints on $w_E$ are consistent with dark energy, while particle creation of pressureless matter is disfavoured. All PC scenarios provide fits comparable to $\hat{I}›$CDM, with one showing effective dynamical dark-energy behaviour. When early- and late-time datasets are analysed separately, the PC models reduce the Hubble tension to $\simeq 2.4\ddot{I}ƒ$--$3\ddot{I}ƒ$, compared to $4.3\ddot{I}ƒ$ in $\hat{I}›$CDM. Gravitationally induced dark energy thus offers a consistent late-time extension of $\hat{I}›$CDM and a viable theoretical framework for dynamical dark energy.

22 pages, 9 figures

References in corpus (1)

• Addressing the DESI DR2 Phantom-Crossing Anomaly and Enhanced $H_0$ Tension with Reconstructed Scalar-Tensor Gravity