Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tutorial on Hybridizable Discontinuous Galerkin (HDG) Formulation for
  Incompressible Flow Problems   A hybridizable discontinuous Galerkin (HDG) formulation of the linearized
incompressible Navier-Stokes equations, known as Oseen equations, is presented.
The Cauchy stress formulation is considered and the symmetry of the stress
tensor and the mixed variable, namely the scaled strain-rate tensor, is
enforced pointwise via Voigt notation. Using equal-order polynomial
approximations of degree k for all variables, HDG provides a stable
discretization. Moreover, owing to Voigt notation, optimal convergence of order
k+1 is obtained for velocity, pressure and strain-rate tensor and a local
postprocessing strategy is devised to construct an approximation of the
velocity superconverging with order k+2, even for low-order polynomial
approximations. A tutorial for the numerical solution of incompressible flow
problems using HDG is presented, with special emphasis on the technical details
required for its implementation.

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The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: solv-int
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: physics
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The categories of this paper are: q-fin