Weak Solutions to a Parabolic-Elliptic System of Chemotaxis

We study a parabolic-elliptic system of partial differential equations, which describes the chemotactic feature of slime molds. It is known that the blowup solution forms singularities such as delta functions, referred to as the collapses. Here, we study the case that the domain is a flat torus and show that the post-blowup continuation of the solution is possible only when those collapses are quantized with the mass 8π.