Cosmological Averaging of Orbital Angular Momentum of Galaxy Clusters A Dynamical Origin Hypothesis for Dark Energy

TThe standard ΛCDM model attributes cosmic accelerated expansion to dark energy, a
mysterious component constituting ∼ 68% of the cosmic energy budget. This leads to the
“fine-tuning” problem: the vacuum energy density predicted by quantum field theory ex
ceeds the observed value by ∼ 120 orders of magnitude. In this paper, we propose that the
observed acceleration need not be powered entirely by dark energy. Instead, a substantial
fraction arises from the cosmological-scale statistical averaging of the orbital angular mo
mentum of the largest gravitationally bound structures—galaxy clusters. Galaxy clusters
acquire orbital angular momentum via tidal torques and form a dynamical equilibrium
with gravity described by the generalized virial theorem. When this equilibrium is grad
ually broken by cluster mass loss and inter-cluster radiation pressure, the stored angular
momentum is released, driving an effective negative pressure. Only a weak residual dark
energy is required to act as a trigger; the main driving force comes from the angular
momentum itself. In this framework, the observationally inferred equation-of-state pa
rameter w(z) is an effective quantity that encapsulates both the weak dark energy and the
angular momentum release. The model predicts a unique arch-shaped evolution of w(z),
testable by upcoming surveys. A slow outward drift of planetary orbits is also predicted
as a local manifestation of the same hierarchical dynamics.
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Keywords: dark energy; orbital angular momentum; galaxy clusters; cosmological aver
aging; tidal torque theory; virial theorem.