ИСТИНА

For a singularly perturbed reaction-diffusion equation, an asymptotic analysis is applied to study the structure of the inner transition layer in the case of a balanced reaction with a weak discontinuity. The existence of solutions with an internal transition layer (contrasting structures) is proved, the question of their stability is investigated, asymptotic approximations of solutions of this type are obtained. It is shown that in the case of reaction balance, the presence of even a weak (asymptotically small) reaction discontinuity can lead to the formation of several contrasting structures of finite size, both stable and unstable.