Non-Commutative fluid: an alternative source of cosmic acceleration

We present a novel formulation for the Hubble parameter derived from Newtonian cosmology, incorporating non-commutative fluid dynamics through a deformed Poisson bracket structure. This approach introduces a new cosmological parameter, denoted by $σ$, which emerges naturally from the underlying non-commutative framework. It gives rise to a source term in the background fluid continuity equation, thereby leading to an apparent type of matter creation picture through the resulting non-conservation. Remarkably, the resulting Hubble function accounts for the observed accelerated expansion of the universe without invoking any external dark energy component or cosmological constant. Instead, the parameter $σ$ effectively serves as the driver of acceleration. We further examine the observational constraints on $σ$ using current cosmological data, including the recent Dark Energy Spectroscopic Instrument(DESI) dataset, demonstrating its viability as an alternative explanation for late-time cosmic acceleration within a non-commutative cosmological model.

💡 Research Summary

The paper proposes a novel cosmological model in which the late‑time accelerated expansion of the universe arises from non‑commutative (NC) corrections to Newtonian fluid dynamics, rather than from a cosmological constant or an explicit dark‑energy component. The authors start by introducing a deformed Poisson‑bracket algebra for the Lagrangian fluid variables (X_i) and their velocities (\dot X_i). In addition to the usual antisymmetric NC parameter (\theta_{ij}) (encoding spatial fuzziness), they introduce a symmetric tensor (\sigma_{ij}) that modifies the mixed position‑momentum brackets. The trace of this tensor, (\sigma \equiv \delta_{ij}\sigma_{ij}), becomes the central cosmological parameter of the model.

Using this algebra, the continuity equation for the background density acquires an extra source term (-\sigma H\rho_0). Consequently the background matter density evolves as (\rho_0\propto a^{-(3+\sigma)}); for (\sigma<0) this mimics effective matter creation, while (\sigma>0) corresponds to an effective depletion. The modified Euler equation together with the continuity relation yields a Friedmann‑type acceleration equation
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