Holographic estimation of multiplicity and membranes collision in   modified spaces ${AdS}_5$
  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 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. To fit the experimental data for multiplicity Kiritsis and Taliotis have proposed to consider black holes formation in modified ${AdS}_5$ spaces with different $b$-factors. In this paper we consider the formation of black holes under collision of membranes in modified ${AdS}_5$ spaces with $b$-factors. Following the previous proposals we consider the power-law and exponential $b$-factors, as well as mixed types of $b$-factors. We study dynamics of the change of the trapped surface area depending on the energy for each investigated space. We find that the power-law and mixed factors fit better to the experimental date. 
I.Ya. Aref'eva, E.O. Pozdeeva, T.O. Pozdeeva
hep-th