Paper detail

Regularity of initial data in dynamical massless scalar field models

We discuss here the issue of regularity of initial data for dynamical spherically symmetric massless scalar field models in a spacetime. Generalizing the known solutions of Einstein equations given in this case by Wyman and Roberts, we examine the issue of regularity on a given spacelike surface, especially when the gradient of the field is spacelike. In particular, we isolate the class of models which would have necessarily a singularity at the center, and therefore these would be unsuitable for studying either gravitational collapse or dynamical evolutions in cosmology.