Holographic estimation of multiplicity and the collision of membranes in modified $\mathrm{AdS}_5$ spaces

The quark–gluon plasma formed as a result of heavy-ion collisions is currently investigated actively both theoretically and experimentally. According to the holographic approach, forming a quark–gluon plasma in the four-dimensional world is associated with creating black holes in a five-dimensional anti-de Sitter (AdS) space. The multiplicity of particles produced in heavy-ion collisions is then determined by the entropy of the five-dimensional black hole, which is estimated by the area of the trapped surface. In this approach, we can model the dependence of the entropy on the energy of the colliding ions and thus the dependence of the multiplicity on the energy, and we can also compare the theoretical results with experimental data. To obtain a variety of model dependences on the energy, we consider the formation of black holes in modified AdS spaces, namely, in AdS spaces with different $b$ factors. We find dynamics of the change of the trapped surface area depending on the energy for each investigated space.