We consider H（curl, Ω）-elliptic variational problems on bounded Lipschitz polyhedra and their finite element Galerkin discretization by means of lowest order edge elements. We assume that the underlying tetrahedral...We consider H（curl, Ω）-elliptic variational problems on bounded Lipschitz polyhedra and their finite element Galerkin discretization by means of lowest order edge elements. We assume that the underlying tetrahedral mesh has been created by successive local mesh refinement, either by local uniform refinement with hanging nodes or bisection refinement. In this setting we develop a convergence theory for the the so-called local multigrid correction scheme with hybrid smoothing. We establish that its convergence rate is uniform with respect to the number of refinement steps. The proof relies on corresponding results for local multigrid in a H^1 （Ω）-context along with local discrete Helmholtz-type decompositions of the edge element space.展开更多
We studied the spectrum and rearrangement decays of S-wave cs■tetraquark states in a simplified quark model.The masses and widths were estimated by assuming that X(4140)is the lower 1^(++)cs■tetraquark.Comparing our...We studied the spectrum and rearrangement decays of S-wave cs■tetraquark states in a simplified quark model.The masses and widths were estimated by assuming that X(4140)is the lower 1^(++)cs■tetraquark.Comparing our results with experimental measurements,we found that X(3960),recently observed by LHCb,can be considered the lowest 0^(++)sc■tetraquark state and X0(4140)could be the second lowest 0^(++)cs■tetraquark.Predictions of ratios between partial widths for the involved tetraquarks are provided in this paper.We aim to identify more cs■tetraquarks with J^(PC)=1^(+-),0^(++),and 2^(++).展开更多
A homological analogue of curve complex of a closed connected orientable surface is developed and studied. The dis-tance in this complex is shown to be quite computable and an algorithm given (Theorem 3.5). As an appl...A homological analogue of curve complex of a closed connected orientable surface is developed and studied. The dis-tance in this complex is shown to be quite computable and an algorithm given (Theorem 3.5). As an application of this complex it is shown that for a closed orientable 3-manifold, and any of its Heegaard splittings, one can give an algorithm to decide whether the manifold contains a 2-sided, non-separating, closed incompressible surface (Theorem 1.1).展开更多
Recently, M. Hanke and M. Neumann([4]) have derived a necessary and sufficient condition on a splitting of A = U-V, which leads to a fixed point system, such that the iterative sequence converges to the least squares ...Recently, M. Hanke and M. Neumann([4]) have derived a necessary and sufficient condition on a splitting of A = U-V, which leads to a fixed point system, such that the iterative sequence converges to the least squares solution of minimum a-norm of the system Ax = b. In this paper, we give a necessary and sufficient condition on the splitting such that the iterative sequence converges to the weighted Moore-Penrose solution of the system Ax = b for every to is an element of C-n and every b is an element of C-m. We also provide a necessary and sufficient condition such that the iterative sequence is convergent for every to x(0) is an element of C-n.展开更多
A quadratic scalar and vector coupling model proposed recently has been applied to finite nuclei.The calculated results are compared with those of the derivative scalar coupling (DSC) model and the nonlinear Walecka m...A quadratic scalar and vector coupling model proposed recently has been applied to finite nuclei.The calculated results are compared with those of the derivative scalar coupling (DSC) model and the nonlinear Walecka model The results show that the spin-orbit splittings are improved considerably by quadratic couplings in contrast to the DSC model However,the binding energy per nucleon,rms charge radius,as well as the spin-orbit splittings in the quadratic model are still small compared with those given by the nonlinear Walecka model and the experimental data.展开更多
This paper is concerned with preconditioners for interior penalty discontinuous Galerkin discretizations of second-order elliptic boundary value problems.We extend earlier related results in[7]in the following sense.S...This paper is concerned with preconditioners for interior penalty discontinuous Galerkin discretizations of second-order elliptic boundary value problems.We extend earlier related results in[7]in the following sense.Several concrete realizations of splitting the nonconforming trial spaces into a conforming and(remaining)nonconforming part are identified and shown to give rise to uniformly bounded condition numbers.These asymptotic results are complemented by numerical tests that shed some light on their respective quantitative behavior.展开更多
基金supported in part by China NSF under the grant 60873177by the National Basic Research Project under the grant 2005CB321702
文摘We consider H（curl, Ω）-elliptic variational problems on bounded Lipschitz polyhedra and their finite element Galerkin discretization by means of lowest order edge elements. We assume that the underlying tetrahedral mesh has been created by successive local mesh refinement, either by local uniform refinement with hanging nodes or bisection refinement. In this setting we develop a convergence theory for the the so-called local multigrid correction scheme with hybrid smoothing. We establish that its convergence rate is uniform with respect to the number of refinement steps. The proof relies on corresponding results for local multigrid in a H^1 （Ω）-context along with local discrete Helmholtz-type decompositions of the edge element space.
基金Supported by the National Natural Science Foundation of China(12235008,12275157,11905114)the Natural Science Foundation of Shandong Province,China(ZR2023MA041)。
文摘We studied the spectrum and rearrangement decays of S-wave cs■tetraquark states in a simplified quark model.The masses and widths were estimated by assuming that X(4140)is the lower 1^(++)cs■tetraquark.Comparing our results with experimental measurements,we found that X(3960),recently observed by LHCb,can be considered the lowest 0^(++)sc■tetraquark state and X0(4140)could be the second lowest 0^(++)cs■tetraquark.Predictions of ratios between partial widths for the involved tetraquarks are provided in this paper.We aim to identify more cs■tetraquarks with J^(PC)=1^(+-),0^(++),and 2^(++).
文摘A homological analogue of curve complex of a closed connected orientable surface is developed and studied. The dis-tance in this complex is shown to be quite computable and an algorithm given (Theorem 3.5). As an application of this complex it is shown that for a closed orientable 3-manifold, and any of its Heegaard splittings, one can give an algorithm to decide whether the manifold contains a 2-sided, non-separating, closed incompressible surface (Theorem 1.1).
文摘Recently, M. Hanke and M. Neumann([4]) have derived a necessary and sufficient condition on a splitting of A = U-V, which leads to a fixed point system, such that the iterative sequence converges to the least squares solution of minimum a-norm of the system Ax = b. In this paper, we give a necessary and sufficient condition on the splitting such that the iterative sequence converges to the weighted Moore-Penrose solution of the system Ax = b for every to is an element of C-n and every b is an element of C-m. We also provide a necessary and sufficient condition such that the iterative sequence is convergent for every to x(0) is an element of C-n.
文摘A quadratic scalar and vector coupling model proposed recently has been applied to finite nuclei.The calculated results are compared with those of the derivative scalar coupling (DSC) model and the nonlinear Walecka model The results show that the spin-orbit splittings are improved considerably by quadratic couplings in contrast to the DSC model However,the binding energy per nucleon,rms charge radius,as well as the spin-orbit splittings in the quadratic model are still small compared with those given by the nonlinear Walecka model and the experimental data.
基金This work has been supported in part by the French-German PROCOPE contract 11418YBby the European Commission Human Potential Programme under contract HPRN-CT-2002-00286“Breaking Complexity”,by the SFB 401 and the Leibniz Pro-gramme funded by DFG.
文摘This paper is concerned with preconditioners for interior penalty discontinuous Galerkin discretizations of second-order elliptic boundary value problems.We extend earlier related results in[7]in the following sense.Several concrete realizations of splitting the nonconforming trial spaces into a conforming and(remaining)nonconforming part are identified and shown to give rise to uniformly bounded condition numbers.These asymptotic results are complemented by numerical tests that shed some light on their respective quantitative behavior.
