Turbulence near cyclic fold bifurcations in birhythmic media.

We show that at the onset of a cyclic fold bifurcation, a birhythmic medium composed of glycolytic oscillators displays turbulent dynamics. By computing the largest Lyapunov exponent, the spatial correlation function, and the average transient lifetime, we classify it as weak turbulence of a transient nature. Virtual heterogeneities generating unstable fast oscillations account for the transient turbulence. In the presence of a wave number instability, unstable oscillations can be reinjected, leading to stationary turbulence. We also find similar turbulence in a cell cycle model. These findings suggest that weak turbulence may be universal in biochemical birhythmic media exhibiting cyclic fold bifurcations.