Group Theoretical Methods in Physics : Proceedings of the XIIth International Colloquium Held at the International Centre for Theoretical Physics, Trieste, Italy September 5-11, 1983

Group Theoretical Methods in Physics: Proceedings of the Xiith International Colloquium Held at the International Centre for Theoretical Physics, Trie

The use and ultimate validity of invariance principles.- Cohomology and contraction: The “non-relativistic” limit revisited.- Linearization — A unified approach.- Weyl kinematical groups of electromagnetic and energy-momentum tensors.- From spinors to probability amplitudes of external and internal variables for spinning particles.- A characterizatton of factor systems of locally-operating representations.- Recent developments on shift operators.- Unitary and non-unitary, multiplicity free irreducible representations of SL (3,R).- The symmetry group of a differential equation.- Group contractions and the E(2)-like little group for massless particles as an infinite-momentum/zero-mass limit of the 0(3)-like little group for massive particles.- Representation approach to lattices of subgroups of space groups.- Young tableaux for the Lie superalgebra OSP(M/N).- The associated Lie Algebra of $$\ddot x$$ + f2 $$\dot x$$ + f1x = f0.- Three-dimensional commutative diagram of group homomorphisms.- Indecomposable representations of Verma type.- Some recent results on the SU(3)? SO(3) state labelling problem.- Irreducible projective representations of the generalized symmetric groups B n m .- Indecomposable representations of some graded Lie Algebras.- Stephen Paneitz: A brief appreciation.- Indecomposable representations of the Poincare group and associated fields.- SL(n,R)/SO(n) unirreps and group decontraction.- Hysteresis & universal bifurcation in natural processes.- Irreducible representations of the basic classical Lie superalgebras SU(m/n) ; SU(n/n)/U(1) ; OSp(m/2n) ; D(2/1 ; ? ) ; G(3) ; F(4)..- Group representations in indefinite metric spaces.- Tensor operator realisations of the classical Lie Algebras and non-trivial zeros of the 6j-symbol.- Yang - Baxter algebras of dynamical charges in the chiral gross - Neveu model.- Subgroups of Lie groups and symmetry reduction for nonlinear partial differential equations.- Spinorial description of Lie superalgebras.- Noetherian symmetries, backlund transformation and conservation laws for a completely integrable three dimensional system.- Einstein equations without killing vectors, self-dual Yang-Mills field and non-linear sigma models (integrability properties, links, new solutions).- Jet bundle technique, Lie Bäcklund vector fields and diffusion equations.- A group-theoretic treatment of Gaussian optics and third-order aberrations.- Study of Michel's conjecture.- Conformally invariant solutions of Yang-Mills equations in Minkowski space.- Two body relativistic scattering with an 0(1,1) symmetric sqaure well potential.- Emergence of central extension of Kac-Moody algebra in quantum integrable models.- Cohomological interpretation of anomalies the example of the trace anomaly.- On pure, conformal and exotic spinors.- Pohlmeyer-type transformations in general relativity.- On group covariance and the law of motion in a generalized metric theory.- Minimalization of Higgs potentials with application to the SU(5) model.- Self-dual monopoles and calorons.- U(1) Invariant hierarchy theories in d-dimension antisymmetric gauge tensor fields.- Generalized connection forms with linearized curvature.- Dynamical symmetry breaking in S4 De Sitter space.- Applications of conformal invariance to gauge Quantum Field Theory.- On the necessity of breaking colour SUC(3) symmetry.- Massive vector superfields with SU(2) internal symmetry.- Supergravity in eleven-dimensional space-time.- Dimensional reduction of exceptional gauge groups and flavor chirality.- Seven - Spheres from octonions.- A solution of Bianchi identities for extended supergravities.- N=2 unconstrained superfield supergravity from hypermultiplet.- Euclidean supersymmetries in three and four dimensions.- Gauge theories in higher dimensions: Linear relations for gauge fields, integrability conditions, spherical symmetry in eight dimensions.- Quantum vortices and diff (?3).- The time dependent Sp(2,?) model for the breathing mode.- The quark structure of nuclei from a group theoretical viewpoint.- Group theoretic approach to spherical anharmonic oscillator.- Operator averages and orthogonalities.- Advances in the theory of collective motion in nuclei.- Quantum effects in classical phase space: Symplectic structures associated to the scattering of nuclear fragments.- Gamow states in momentum representation.- Geometry of nuclear collective motions.- Is it possible to separate the kinetic energy and the velocity field into a collective and an intrinsic part W.R.T. the GL+(3,)R) collectivity?.- Computer generated Clebsch-Gordan (C-G) coefficients for space groups.- Automorphism symmetries of space group representations.- Lattices of symmetric groups S5 and S6 and exomorphism of group-subgroup relations up to index 6.- A direct-expansion method for tensor properties of crystals.- Isotropy groups of space groups — A simple method for their determination.- Landau's theory of crystalline phase transitions in a superspace formulation.- Symmetry breaking in solid state and particle physics.- Counterexamples to the maximality conjecture of Landau-Higgs models.- Some mathematical problems in renormalization group theory.- On the Racah algebra for Shubnikov magnetic groups.- On periodic and non-periodic space fillings of Em obtained by projection.- Invariants for physically irreducible representations of space groups.- On symmetry aspects of phase transitions with coupled parameters.- Quasisymmetry (P-symmetry) in crystals.- Braid groups and Euclidean Lie algebras in statistical mechanics of spin systems.- Phase coexistence in many-fermion systems.- Mean field renormalization group approach to lattice models.- Linear-antilinear representations of magnetic line groups.- Anderson transition and nonlinear ?-model.- Do energy bands in solids have an identity.- Coupling coefficients for the space group of the hexagonal close-packed structure.- Harmonic analysis on phase space and Born's metric for space time.- Generalized Chebyshev polynomials and characters of GL(N,C) and SL(N,C) (fragments of results).- Tensor operators as an extension of the universal enveloping algebra.- A group-theoretical criterion for an Einstein-Podolsky-Rosen state.- Group theory algebras and bosonization.- SO(3) commutators for angular momentum and rotation observables.- Integrals of motion of nonstationary quantum systems.- Geometric properties of the lowest energy state for a polynomial Hamiltonian.- Groupes différentiels et physique mathématique.- Gauge invariance and canonical transformations in Dirac generalized mechanics.