In this paper a hybridized weak Galerkin (HWG) finite element method for
solving the Stokes equations in the primary velocity-pressure formulation is
introduced. The WG method uses weak functions and their weak derivatives which
are defined as distributions. Weak functions and weak derivatives can be
approximated by piecewise polynomials with various degrees. Different
combination of polynomial spaces leads to different WG finite element methods,
which makes WG methods highly flexible and efficient in practical computation.
A Lagrange multiplier is introduced to provide a numerical approximation for
certain derivatives of the exact solution. With this new feature, HWG method
can be used to deal with jumps of the functions and their flux easily. Optimal
order error estimate are established for the corresponding HWG finite element
approximations for both {\color{black}primal variables} and the Lagrange
multiplier. A Schur complement formulation of the HWG method is derived for
implementation purpose. The validity of the theoretical results is demonstrated
in numerical tests.Comment: 19 pages, 4 tables,it has been accepted for publication in SCIENCE
CHINA Mathematics. arXiv admin note: substantial text overlap with
arXiv:1402.1157, arXiv:1302.2707 by other author