Generation and control of chaos in a Bose-Einstein condensate

For a Bose-Einstein condensate （BEC） confined in a double lattice consisting of two weak laser standing waves we find the Melnikov chaotic solution and chaotic region of parameter space by using the direct perturbation method. In the chaotic region, spatial evolutions of the chaotic solution and the corresponding distribution of particle number density are bounded but unpredictable between their superior and inferior limits. It is illustrated that when the relation k1≈ k2 between the two laser wave vectors is kept, the adjustment from k2 〈 k1 to k2 ≥ k1 can transform the chaotic region into regular one or the other way round. This suggests a feasible scheme for generating and controlling chaos, which could lead to an experimental observation in the near future.

On maximal non-selfadjoint reflexive algebras associated with a double triangle lattice

We show that the reflexive algebra Alg(L) given by a double triangle lattice L in a finite factor M(with L" = M) is maximal non-selfadjoint in the class of all weak operator closed subalgebras with the same diagonal subalgebra Alg(L) ∩ Alg(L)^+.Our method can be used to prove similar results in finite-dimensional matrix algebras.As a consequence,we give a new proof to the main theorem by Hou and Zhang(2012).

φ-Derivations on Strongly Double Triangle Subspace Lattice Algebras

Let D= {{0},/4, L, M, X} be a strongly double triangle subspace lattice on a nonzero complex reflexive Banach space X, which satisfies that one of three sums K ＋ L, L＋M and M ＋ K is closed. It is shown that local C-derivations and C-derivations at zero point on Alg：D are generalized Ф-derivations.

On Strong Kadison–Singer Algebras

We show that many Kadison-Singer algebras are maximal triangular in all algebras containing them although their definition requires the maximality taken in the class of reflexive algebras. Diagonal-trivial maximal non self-adjoint subalgebras of matrix algebras with lower dimensions are classified.