It is shown that for both the Hartree-Fock and Bogoliubov models of interacting bosons associated with the disappearance of the Bose-Einstein condensation at a temperature $T_c$, the specific heat $C_V$ has a square root singularity, $C_V\sim A{(T_c-T)}^{-\frac{1}{2}}$, and the superfluid density ${\rho }_S$ is discontinuous, with ${\rho }_S\mathrm{}\left(T\right)-{\rho }_S(T_c-0)\sim B{(T_c-T)}^{\frac{1}{2}}$ for temperatures $T\to T_c-0\mathrm{}$. Except near $T_c=T_{\lambda }$ the theoretical and experimental results for ${\rho }_S$ are in good agreement.

Dispersion has been observed in the Brillouin components of the light-scattering spectrum of triglycine sulfate. It is attributed to the Landau-Khalatnikov relaxation of fluctuations in the spontaneous polarization.

The diffusion coefficient describing the motion of cosmic-ray particles in the interplanetary magnetic field is determined from the power spectrum of magnetic irregularities observed on space probes, and is found to be proportional to $R\beta$ ($R=\mathrm{particle}\mathrm{magnetic}\mathrm{rigidity}$, $\beta =\mathrm{particle}\mathrm{velocity}$). Near minimum solar activity, only this dependence of the diffusion coefficient on $R$ and $\beta$ can account for the observed long-term intensity variations of cosmic-ray protons and helium nuclei down to 10 MeV per nucleon in energy. Thus, the motion of cosmic rays in interplanetary space may be quantitatively related to the observed magnetic field.

It is shown explicitly that for finite-range two-body forces which contribute significant interactions in only $L+1\mathrm{}$ orbital angular momentum states, the Faddeev equations for the three-body $T$ matrix with total angular momentum $J$ can be reduced to well-defined integral equations for functions of two continuous variables with $3(L+1\mathrm{})\mathrm{}\times min(2J+1, 2L+1)$ components. Hence numerical calculation for realistic interactions, and analytic investigation of the dependence on two-body dynamics (which is explicitly separated from the geometrical part of the problem), become possible.

An upper limit of 0.50 (90% confidence level) is set for the branching ratio $\frac{(\eta \to {\pi }^0+\gamma +\gamma )}{(\eta \to \gamma +\gamma )}$ in a spark-chamber experiment measuring ${\pi }^{-}+p\to (n+4\mathrm{}\gamma \mathrm{and} n+2\mathrm{}\gamma )$ at 10 BeV/c. This disagrees with a recent measurement of 0.90±0.10 for the same ratio.