Observational constraints on Luciano-Saridakis holographic dark energy

Abstract

Holographic dark energy (HDE) models provide a natural framework for linking gravitational thermodynamics to the late-time accelerated expansion of the Universe. In this work, we investigate the observational viability of an extended HDE scenario arising from a recently proposed generalized entropy. For bounded systems, this entropy exhibits a generalized holographic scaling with two independent area contributions, giving rise to a modified HDE density that encompasses both standard HDE and $\Lambda$CDM as limiting cases. Focusing on the Hubble-horizon infrared cutoff, we constrain the model using Cosmic Chronometers, the Pantheon${}^{+}$+SH0ES Type Ia supernova compilation, DESI DR2 baryon acoustic oscillations, and compressed Planck 2018 CMB shift parameters. We find that the model provides an excellent fit to the combined dataset and admits regions of parameter space in which the Pantheon${}^{+}$+SH0ES and CMB constraints can be simultaneously accommodated. The preferred solutions lie close to the $\Lambda$CDM regime, although non-standard entropic contributions remain compatible with current observations. We further compare the complete realization of the model, containing both independent area contributions, with its reduced single-contribution limit, finding that both provide essentially equivalent descriptions of the data, with a mild preference for the latter. Our results establish generalized entropic HDE as a viable and theoretically motivated extension of the standard cosmological scenario and provide the first observational assessment of this cosmological framework.

Comments: 12 pages, 6 figures