The article is a report on the biography and achievements of Ernest Borisovich Vinberg, an outstanding Russian mathematician, who passed away in Moscow on May 12, 2020. We discuss his contributions to various areas of mathematics such as Riemannian and Lobachevsky geometries, homogeneous convex cones, Lie groups and Invariant theory, equivariant symplectic geometry and Poisson structures.

These two volumes contain 18 invited papers in honour of the 80th birthday of mathematician Israel M. Gelfand, who is considered to have played an important role in the development of functional analysis in the latter half of the 20th century. The papers cover areas in which Gelfand has a strong interest, including geometric quantum field theory, representation theory, combinatorial structures underlying various "continuous" constructions, quantum groups and geometry. The second volume contains the more "geometric" papers.