Symmetry (physics)

About: Symmetry (physics) is a research topic. Over the lifetime, 26435 publications have been published within this topic receiving 500189 citations. The topic is also known as: symmetry (physics) & physical symmetry.

Perturbation theory about a goldstone symmetry.

Abstract: We show that if a Hamiltonian symmetry is realized by Goldstone bosons then, in general, one does not expect the $S$-matrix and matrix elements of currents to be analytic functions of the symmetry-breaking parameters. This modifies the nonrenormalization theorems for vector form factors and some theorems of Dashen and Weinstein.

Baryon-Pion Couplings from Large-N QCD

Abstract: We derive a set of consistency conditions for the pion-baryon coupling constants in the large-N limit of QCD. The consistency conditions have a unique solution which are precisely the values for the pion-baryon coupling constants in the Skyrme model. We also prove that non-relativistic $SU(2N_f)$ spin-flavor symmetry (where $N_f$ is the number of light flavors) is a symmetry of the baryon-pion couplings in the large-N limit of QCD. The symmetry breaking corrections to the pion-baryon couplings vanish to first order in $1/N$. Consistency conditions for other couplings, such as the magnetic moments are also derived.

On simple saddle points of a potential surface, the conservation of nuclear symmetry along paths of steepest descent, and the symmetry of transition states

Abstract: We show that if the transition state of a chemical reaction is a simple saddle point of the potential surface linked directly with reactants and products by paths of steepest descent, then the symmetry of the transition state is limited to the joint symmetry of reactant and product, unless reactant and product are physically indistinguishable and themselves symmetry related, in which case the transition state may have those additional symmetries that interchange reactant and product. We outline some of the general consequences of this symmetry restriction on transition states.

Dynamical Generation of Four-Dimensional Space-Time in the IIB Matrix Model

Abstract: We study the spontaneous breakdown of SO(10) symmetry in the IIB matrix model, a conjectured nonperturbative definition of type IIB superstring theory in ten dimensions. Our analysis is based on a gaussian expansion technique, which was originally proposed by Kabat-Lifschytz and applied successfully to the strong coupling dynamics of the Matrix Theory. We propose a prescription for including higher order corrections, which yields a rapid convergence in a simple example. This prescription is then applied to the IIB matrix model up to the third order. We find that the `self-consistency equations' allow various symmetry breaking solutions. Among them, the solution preserving SO(4) symmetry is found to have the smallest free energy. The value of the free energy comes closer to the analytic formula obtained by Krauth-Nicolai-Staudacher as we increase the order. The extent of the space-time in the 4 directions is larger than the remaining 6 directions, and the ratio increases with the order. These results provide the first analytical evidence that four-dimensional space-time is generated dynamically in the IIB matrix model.