A dipolar droplet bound in a trapped Bose-Einstein condensate

We study the statics and dynamics of a dipolar Bose-Einstein condensate (BEC) droplet bound by inter-species contact interaction in a trapped non-dipolar BEC. Our findings are demonstrated in terms of stability plots of a dipolar 164Dy droplet bound in a trapped non-dipolar 87Rb BEC with a variable number of 164Dy atoms and the inter-species scattering length. A trapped non-dipolar BEC of a fixed number of atoms can only bind a dipolar droplet containing atoms less than a critical number for the inter-species scattering length between two critical values. The shape and size (statics) as well as the small breathing oscillation (dynamics) of the dipolar BEC droplet are studied using the numerical and variational solutions of a mean-field model. We also suggest an experimental procedure for achieving such a 164Dy droplet by relaxing the trap on the 164Dy BEC in a trapped binary 87Rb-164Dy mixture

Mixing, demixing, and structure formation in a binary dipolar Bose-Einstein condensate

We study static properties of disk-shaped binary dipolar Bose-Einstein condensates of $^{168}$Er-$^{164}$Dy and $^{52}$Cr-$^{164}$Dy mixtures under the action of inter- and intra-species contact and dipolar interactions and demonstrate the effect of dipolar interaction using the mean-field approach. Throughout this study we use realistic values of inter- and intra-species dipolar interactions and the intra-species scattering lengths and consider the inter-species scattering length as a parameter. The stability of the binary mixture is illustrated through phase plots involving number of atoms of the species. The binary system always becomes unstable as the number of atoms increases beyond a certain limit. As the inter-species scattering length increases corresponding to more repulsion, an overlapping mixed state of the two species changes to a separated demixed configuration. During transition from a mixed to a demixed configuration as the inter-species scattering length is increased for parameters just below the stability line, the binary condensate shows special structures in density in the form of red-blood-cell-like biconcave and Saturn-ring-like shapes, which are direct manifestations of dipolar interaction

Statics and dynamics of a binary dipolar Bose-Einstein condensate soliton

We study the statics and dynamics of a binary dipolar Bose-Einstein condensate soliton for repulsive inter- and intraspecies contact interactions with the two components subject to different spatial symmetries $-$ distinct quasi-one-dimensional and quasi-two-dimensional shapes - using numerical solution and variational approximation of a three-dimensional mean-field model. The results are illustrated with realistic values of parameters in the binary 164Dy-168Er mixture. The possibility of forming robust dipolar solitons of very large number of atoms make them of great experimental interest. The existence of the solitons is illustrated in terms of stability phase diagrams. Exotic shapes of these solitons are illustrated in isodensity plots. The variational results for statics (size and chemical potential) and dynamics (small oscillation) of the binary soliton compare well with the numerical results. A way of preparing and studying these solitons in laboratory is suggested

Childhood predictors of criminal offending: results from a 19-year longitudinal epidemiological study of boys

Objective: To examine the relative contribution of hyperactivity, conduct, and emotional problems in predicting criminal offending. Method: In all, 173 boys aged 6 to 8 years (assessed for hyperactivity, conduct, and emotional problems) were followed up 19 years later by examining criminal offense histories. Results: Significant main effects for total and violent convictions were found, the strongest being for violent criminal offenses. Conduct problems predicted general offending (irrespective of the type of conviction), whereas emotional problems were the single best predictor of violent convictions. Hyperactivity was not a significant predictor in the models. Conclusion: The findings provide insight into the developmental mechanisms that mediate criminal behavior by showing that childhood emotional problems independently contribute to the risk of violent offending in later

Path description of type B q-characters

We give a set of sufficient conditions for a Laurent polynomial to be the q-character of a finite-dimensional irreducible representation of a quantum affine group. We use this result to obtain an explicit path description of q-characters for a class of modules in type B. In particular, this proves a conjecture of Kuniba-Ohta-Suzuki.Comment: 32 pages, late

The Molecular Gas Distribution and Schmidt Law in M33

The relationship between the star formation rate and surface density of neutral gas within the disk of M33 is examined with new imaging observations of CO J=1-0 emission gathered with the FCRAO 14m telescope and IRAS HiRes images of the 60 micron and 100 micron emission. The Schmidt law, Sigma_SFR ~ Sigma_gas^n, is constructed using radial profiles of the HI 21cm, CO, and far infrared emission. A strong correlation is identified between the star formation rate and molecular gas surface density. This suggests that the condensation of giant molecular clouds is the limiting step to star formation within the M33 disk. The corresponding molecular Schmidt index, n_{mol}, is 1.36 +/- 0.08. The star formation rate has a steep dependence on total mass gas surface density, (Sigma_{HI}+Sigma_{H_2}), owing to the shallow radial profile of the atomic gas which dominates the total gas surface density for most radii. The disk pressure of the gas is shown to play a prominent role in regulating the molecular gas fraction in M33.Comment: 19 pages + 5 figures. Accepted for publication in Ap