We give a characterization of limits of dihedral groups in the space of finitely generated marked groups. We also describe the topological closure of dihedral groups in the space of marked groups on a fixed number of generators.

We show that the homotopy type of a finite oriented Poincar\'{e} 4-complex is determined by its quadratic 2-type provided fundamental group and has dihedral Sylow 2-subgroup. By combining with results Hambleton-Kreck Bauer, this applies in case smooth 4-manifolds whose subgroup SO(3). An important class examples are elliptic surfaces group.

‎Let $Gamma$ be a graph with adjacency eigenvalues $lambda_1leqlambda_2leqldotsleqlambda_n$‎. ‎Then the energy of‎ ‎$Gamma$‎, ‎a concept defined in 1978 by Gutman‎, ‎is defined as $mathcal{E}(G)=sum_{i=1}^n|lambda_i|$‎. ‎Also‎ ‎the Estrada index of $Gamma$‎, ‎which is defined in 2000 by Ernesto Estrada‎, ‎is defined as $EE(Gamma)=sum_{i=1}^ne^{lambda_i}$‎. ‎In this paper‎, ‎we compute the eigen...

In the title compound, C(30)H(20)N(2)O(2), the orientation of the furyl group may induce a variety of coordination modes with this ligand. The dihedral angle between the two naphthyl rings is 79.25 (7)°. The furyl groups make dihedral angles of 62.0 (1) and 16.3 (2)° with the attached naphthyl groups. The dihedral angle between the two furyl rings is 49.3 (2)°.

In this paper, we find a strong new restriction on the structure of CI-groups. We show that, if R is generalised dihedral group and CI-group, then for every odd prime p Sylow p-subgroup has order p, or 9. Consequently, any CI-group with quotient same restriction, that

In the title compound, C(14)H(12)ClNO, the central acetamide plane forms dihedral angles of 76.0 (2) and 64.0 (2)° with the phenyl rings and the phenyl rings form a dihedral angle of 71.8 (2)° with each other.