# Formation of caustics in k-essence and Horndeski theory

@article{Babichev2016FormationOC, title={Formation of caustics in k-essence and Horndeski theory}, author={Eugeny Babichev}, journal={Journal of High Energy Physics}, year={2016}, volume={2016}, pages={1-18} }

A bstractWe study propagation of waves and appearance of caustics in k-essence and galileon theories. First we show that previously known solutions for travelling waves in k-essence and galileon models correspond to very specific fine-tuned initial conditions. On the contrary, as we demonstrate by the method of characteristics, generic initial conditions leads to a wave in k-essence which ends up with formation of caustics. Finally, we find that any wave solution in pure k-essence is also a…

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