String-field theory of $D$-branes

Superstring theory is a universal theory describing all known interactions of elementary particles. One of the most striking non-perturbative effects in string theory is the existence of so-called $D$-branes, the string analogue of solitons. Boson $D$-branes are generally studied on the basis of Witten's boson field action. Research into superstring $D$-branes based on the cubic superstring field action, generalizing the boson action, was described, including, in particular, the decay of non-stable non-extremal $D$-branes into a stable state, the theory in a neighbourhood of a stable state, and possible applications to cosmology.