Predissociation in the HNO molecule

The line broadening in the A¹ A″ -X¹ A′ absorption spectrum of HNO has been studied at high resolution. An accidental predissociation route via the X¹ A′ state is suggested as the predominant mechanism for the predissociation in the A¹ A″ state.     

Multiplet shortening in Osp(N,4)

We describe a new type of multiplet shortening in Osp(N,4) which resolves a long-standing puzzle in Kaluza-Klein supergravities. Multiplet shortening implies quantization of mass eigenvalues in units of the inverse AdS radius. While detailed proofs are presented only for N = 3, we discuss implications for N = 8 supergravity and derive the SO(8) assignments of all higher modes on the round seven-sphere.     

On the “overlapping resonances” concept of acoustic transmission through an elastic plate,II: Numerical examples and physical implications

In a companion paper [1] the Fiorito, Madigosky and Überall approximate theory of transmittivity of an infinite, isotropic, elastic plate in terms of Lamb mode resonances [2] is examined, and extended by validating coherent addition of these overlapping resonances. The present paper provides numerical and heuristic tests which yield convincing proof of the applicability of the overlapping resonances concept. At various thicknesses of a water-immersed, steel plate, including the half-space and zero thickness limits, the behaviour is shown to be compatible with known exact behaviour. Overlapping resonances explain the reduction towards zero of the transmittivity near the coincidence angles of the zero order Lamb modes as these converge to the Rayleigh angle. Contrary to earlier interpretations, both zero order modes survive at the half-space limit. The A₀ mode is shown to contribute below (fd)_critical, becoming then highly damped and, effectively, non-propagating. The interpretation provided of the transition of the A₀ mode in this region bridges the gap between conventional Lamb mode theory and thin plate theory.     

Antisymmetric tensor gauge theories and non-linear σ-models

Antisymmetric tensor fields B_μν subject to the gauge transformation δB_μν = ?_μξ_ν ? ?_νξ_μ can describe spinless particles. We investigate the properties of field theories with a “non-abelian generalization” of this invariance. One class of such theories is equivalent to non-linear principal chiral σ-models, another to massive Yang-Mills theories. A supersymmetric analogue in 2 + 2 superspace is constructed and leads to the supersymmetric σ-model defined on a general riemannian manifold.     

A central limit theorem for empirical histograms

Probability Theory and Related Fields -     

Synthesis,structure elucidation and antibacterial activity of 6-ethyl-6,9-dihydro-9-oxopyrazolo[3,4-f]quinoline-8-carboxylic acid

The preparation, structure elucidation and antibacterial activity of 6-ethyl-6,9-dihydro-9-oxopyrazolo-[3,4-f]quinoline-8-carboxylic acid are reported.     

On the energy-momentum tensor in gauge field theories

The energy-momentum tensor in spontaneously broken non-Abelian gauge field theories is studied. The motivation is to show that recent results on the finiteness and gauge independence of S-matrix elements in gauge theories extends to observable amplitudes for transitions in a gravitational field. Path integral methods and dimensional regularization are used throughout. Green's functions Γ_μν^(j)(q; p₁,…,p_j) involving the energy-momentum tensor and j particle fields are proved finite to all orders in perturbation theory to zero and first order in q, and finite to one loop order for general q. Amputated Green's functions of the energy momentum tensor are proved to be gauge independent on mass shell.     

A statistical approach to quantum mechanics

A Monte Carlo method is used to evaluate the Euclidean version of Feynman's sum over particle histories. Following Feynman's treatment, individual paths are defined on a discrete (imaginary) time lattice with periodic boundary conditions. On each lattice site, a continuous position variable x_i specifies the spacial location of the particle. Using a modified Metropolis algorithm, the low-lying energy eigenvalues, |ψ₀(x)|², the propagator, and the effective potential for the anharmonic oscillator are computed, in good agreement with theory. For a deep double-well potential, instantons were found in our computer simulations appearing as multi-kink configurations on the lattice.