We show that a momentum operator of a translational symmetry may not commute with an internal symmetry operator in the presence of a topological soliton in nonrelativistic theories. As a striking consequence, there appears a coupled Nambu-Goldstone mode with a quadratic dispersion consisting of translational and internal zero modes in the vicinity of a domain wall in an O(3) σ model, a magnetic...

We present a dynamical mean-field study of antiferromagnetic magnons in one-, two- and three-orbital Hubbard model square bcc cubic lattice at intermediate coupling strength. Weinvestigate the effect anisotropy introduced by an external magnetic field or single-ion anisotropy.For latter we tune continuously between easy-axis easy-plane models. also analyzea with spin-orbit site-symmetry setting...

The whole mol-ecule of the title compound, C16H18O4, is generated by twofold rotational symmetry; the twofold axis bis-ects the central C-C bond. The O-C-C-O torsion angle about the central C-C bond is 69.45 (16)°. Symmetry-related benzene rings are inclined to one another by 64.91 (8)°. In the crystal, mol-ecules are connected by C-H⋯O hydrogen bonds, forming a three-dimensional network.

In the crystal structure of the title compound, [Cu(C(18)H(15)As)(4)]PF(6), the Cu atom is coordinated by four As atoms of triphenyl-arsine ligands in a tetra-hedral geometry. The complex cation is located on a crystallographic threefold axis. Both PF(6) (-) anions are located on special positions of site symmetry . The Cu-As bond of the independent arsine ligand is shorter than the Cu-As bonds...

In the title sinomenine derivative, C(26)H(28)FNO(4)·1.5H(2)O, the dihedral angle between the two aromatic rings is 55.32 (6)°. The N-containing ring has an approximate chair conformation, while other two rings have approximate envelope and half-chair conformations. One water mol-ecule is located on a twofold symmetry axis. In the crystal, the water mol-ecules form O-H⋯O and O-H⋯N hydrogen bond...

The asymptotic behavior of Einstein-Rosen waves at null innnity in 4 dimensions is investigated in all directions by exploiting the relation between the 4-dimensional space-time and the 3-dimensional symmetry reduction thereof. Somewhat surprisingly, the behavior in a generic direction is better than that in directions orthogonal to the symmetry axis. The geometric origin of this diierence can ...

The two halves of the title compound, [Cu(C(2)H(2)BrO(2))(2)(C(12)H(8)N(2))], are related by twofold symmetry along the b axis through the central Cu(II) ion. The Cu(II) ion is coordinated by two symmetry-related N atoms from the 1,10-phenanthroline ligand and four O atoms from two 2-bromo-acetate ligands, showing a distorted octahedral geometry. Weak inter-molecular C-H⋯O inter-actions link ne...

The complete organic molecule in the title dihydrate, C(20)H(22)N(4)O(4), is generated by crystallographic twofold symmetry, with two C atoms lying on the rotation axis. The symmetry unique pyridine ring forms a dihedral angle of 83.16 (8)° with the central benzene ring. In the crystal, inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds connect the components into a two-dimensional network l...

The asymptotic behavior of Einstein-Rosen waves at null infinity in 4 dimensions is investigated in all directions by exploiting the relation between the 4-dimensional space-time and the 3-dimensional symmetry reduction thereof. Somewhat surprisingly, the behavior in a generic direction is better than that in directions orthogonal to the symmetry axis. The geometric origin of this difference ca...

The fundamental relations governing the geometry of carbon nanotubes are reviewed, and explicit examples are presented. A framework is given for the symmetry properties of carbon nanotubes for both symmorphic and non-symmorphic tubules which have screw-axis symmetry. The implications of symmetry on the vibrational and electronic structure of ID carbon nanotube systems are considered. The corres...