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arXiv · 2310.03697

Onset of dark energy from cosmological scalarization and gravitational wave speed

H. Mohseni Sadjadi
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Abstract

This study investigates the emergence of dark energy during the matter-dominated era through spontaneous cosmological scalarization in the scalar-Ricci-Gauss-Bonnet model.Our model aligns with the conjecture that the speed of gravitational waves at low redshifts is nearly equal to the speed of light, implying that the Gauss-Bonnet invariant does not directly contribute to late-time acceleration and suggesting that scalarization begins in the radiation-dominated era. The Gauss-Bonnet coupling stabilizes the quintessence field at an initial fixed point with negligible dark energy density during the radiation era. As the Universe expands, the Ricci coupling induces a tachyonic transition in the quintessence field, driving the evolution of dark energy.

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H. Mohseni Sadjadi. 2023-10-05. Onset of dark energy from cosmological scalarization and gravitational wave speed. https://doi.org/10.1007/s10714-025-03431-z

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