Accurate and efficient numerical methods for computing ground states and dynamics of dipolar Bose-Einstein condensates via the nonuniform FFT

In this paper, we propose efficient and accurate numerical methods for computing the ground state and dynamics of the dipolar Bose-Einstein condensates utilising a newly developed dipole-dipole interaction (DDI) solver that is implemented with the non-uniform fast Fourier transform (NUFFT) algorithm. We begin with the three-dimensional (3D) Gross-Pitaevskii equation (GPE) with a DDI term and present the corresponding two-dimensional (2D) model under a strongly anisotropic confining potential. Different from existing methods, the NUFFT based DDI solver removes the singularity by adopting the spherical/polar coordinates in Fourier space in 3D/2D, respectively, thus it can achieve spectral accuracy in space and simultaneously maintain high efficiency by making full use of FFT and NUFFT whenever it is necessary and/or needed. Then, we incorporate this solver into existing successful methods for computing the ground state and dynamics of GPE with a DDI for dipolar BEC. Extensive numerical comparisons with existing methods are carried out for computing the DDI, ground states and dynamics of the dipolar BEC. Numerical results show that our new methods outperform existing methods in terms of both accuracy and efficiency.Comment: 26 pages, 5 figure

Triton-3He relative and differential flows and the high density behavior of nuclear symmetry energy

Using a transport model coupled with a phase-space coalescence after-burner we study the triton-3He relative and differential transverse flows in semi-central 132Sn+124Sn reactions at a beam energy of 400 MeV/nucleon. We find that the triton-3He pairs carry interesting information about the density dependence of the nuclear symmetry energy. The t-3He relative flow can be used as a particularly powerful probe of the high-density behavior of the nuclear symmetry energy.Comment: 6 pages, 2 figures, Proceeding of The International Workshop on Nuclear Dynamics in Heavy-Ion Reactions and the Symmetry Energ

Double neutron-proton differential transverse flow as a probe for the high-density behavior of the nuclear symmetry energy

The double neutron-proton differential transverse flowtaken from two reaction systems using different isotopes of the same element is studied at incident beam energies of 400 and 800 MeV/nucleon within the framework of an isospin- and momentum-dependent hadronic transport model IBUU04. The double differential flow is found to retain about the same sensitivity to the density dependence of the nuclear symmetry energy as the single differential flow in the more neutron-rich reaction. Because the double differential flow reduces significantly both the systematic errors and the influence of the Coulomb force, it is thus more effective probe for the high-density behavior of the nuclear symmetry energy.Comment: 12 pages, 6 figures, version accepted for publication in Phys. Rev.

A genetic study on the activiation of quiescent Uq transposable elements in Zea mays L.

The standard a-ruq allele reports the activity of the Uq transposable element in the form of color spots or sectors of color spots in otherwise colorless aleurone tissue. As reported by this a-ruq, genomes of four maize inbred lines (C123, C103, B70 and 187-2) lack an active Uq element. However, these genomes contain quiescent Uq sequences that randomly and infrequently become activated;Spontaneous activation of quiescent Uq sequences during development of a-ruq/a-ruq/a-ruq endosperm results in sectors of Uq-a-ruq spotting in otherwise colorless aleurone tissue;Spontaneous germinal activation (at a rate of about 2 x 10[superscript]-4) of quiescent Uq sequences produces individual fully-spotted exceptional kernels of a-ruq/a-ruq/a-ruq genotype. Their spotting patterns differ from the pattern of the standard Uql-a-ruq spotting. Five new Uq elements, designated Uq2, Uq3, Uq4, Uq5, and Uq6, respectively, have been isolated. The genetic authenticity of these new Uq elements has been established;These five new Uq elements are independent of Uq1 and are clustered on one linkage group. Uq2 is allelic to Uq4, Uq3 is allelic to Uq5, whereas Uq6 is linked to both allelic pairs;Another quiescent Uq element has been activated in a maize plant upon treatment with 5-aza-2[superscript]\u27-deoxycytidine. This Uq consegregates with a coinduced miniature mutant that is found to be independent of mn1, mn2, and mn7690. The cosegregating genetic unit, designated Mn::Uq, acts dominantly and is not male transmissable. An in vitro pollen germination study shows that Mn::Uq pollen does not germinate, thereby causing this male nontransmissibility. Definitive genetic proof for the Uq nature of the mutant is given by the fact that a reconstitution testcross between a°/a°, Mn::Uq/+ and the a-ruq/a-ruq tester produces 50% spotted miniature and 50% colorless normal progeny;The Mn::Uq mutant does not transactivate the c-ruq65 and c-ruq67 alleles, two other Uq1-responding reporter alleles. In addition, Ug3, Ug4, and Ug5 transactivate the c-ruq alleles in a much weaker fashion than they transactivate a-ruq. These results suggest that structural differences may exist between these ruq receptor elements at the a-ruq and c-ruq alleles