Partecipanti: Dr. Katy Clough: Goettingen University
Abstract: The relativistic dynamics of scalar fields which are subject to a non trivial self interaction potential are extremely rich and relevant to a number of theoretical problems. Using full 3+1 Numerical Relativity, many open problems which defy a perturbative approach can be solved, including the behaviour of the axion field in strong gravity. In https://arxiv.org/abs/1609.04724 we studied the stability and collapse of localised disturbances in the axion field and identified three regions of the parameter space: i) long-lived oscillating axion star solutions, with a base frequency modulated by self-interactions, ii) collapse to a BH and iii) complete dispersal due to gravitational cooling and interactions. I will discuss the results of our paper, the follow up work which others have done in interpreting and extending the result, and future directions of study.