The contents survey the achievements and research problems connected with an adequate description of condensed matter structure, its phases and other properties in terms of appropriate mathematical tools. The focus is on the following topics: Action of groups on sets and broken symmetries; Racah-Wigner approach to vibrations, electronic states, correlations and superconductivity in multicenter systems; crystallography and its extension.

These proceedings review the recent developments in current research connected with an adequate description of condensed matter in statistics of quasiparticles, topological invariants and self-similar structures.

This volume reviews some selected problems in solid state physics with an emphasis on adequate mathematical tools. The three main subjects are magnetic structures and neutron scattering; Berry phases and energy bands in solids (symmetry, analicity, Hofstadter butterfly, van Hove singularities); and quasicrystals, finite systems, and group action on sets (unitary group approach, Schur functions). Software presentations are included as a separate part.

The contents survey the achievements and research problems connected with an adequate description of condensed matter structure, its phases and other properties in terms of appropriate mathematical tools. The focus is on the following topics: Action of groups on sets and broken symmetries; Racah-Wigner approach to vibrations, electronic states, correlations and superconductivity in multicenter systems; crystallography and its extension.

These proceedings review the recent developments in current research connected with an adequate description of condensed matter in statistics of quasiparticles, topological invariants and self-similar structures.

This volume reviews some selected problems in solid state physics with an emphasis on adequate mathematical tools. The three main subjects are magnetic structures and neutron scattering; Berry phases and energy bands in solids (symmetry, analicity, Hofstadter butterfly, van Hove singularities); and quasicrystals, finite systems, and group action on sets (unitary group approach, Schur functions). Software presentations are included as a separate part.