From: Jiaqi Zhang <jiaqi2@clemson.edu>
Date: Sat, 19 Jun 2021 12:37:45 +0000 (-0400)
Subject: step-74 description
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=89f05b181899182c2626d5c73b99f2817645e0a1;p=release-papers.git

step-74 description
---

diff --git a/9.3/paper.tex b/9.3/paper.tex
index 1b75055..f01f43d 100644
--- a/9.3/paper.tex
+++ b/9.3/paper.tex
@@ -1089,7 +1089,13 @@ framework in parallel. The PDE considered is the Gelfand problem $-\triangle u =
   or alternatively as the second derivative of an energy functional
   that then also yields the residual itself.
 
-\item \texttt{step-74} SIPG for the Poisson equation \todo[inline]{TODO}
+\item \texttt{step-74} implements the symmetric interior penalty Galerkin 
+(SIPG) method for Poisson's equation using the \texttt{FEInterfaceValues} class
+in combination with \texttt{MeshWorker::mesh\_loop()}. With \texttt{FEInterfaceValues},
+we can directly obtain the jump and the average of shape functions and of the solution 
+across cell faces, which simplifies the assembling of face terms in DG methods especially on 
+adaptive meshes. 
+
   
 \item \texttt{step-75} demonstrates a state-of-the-art way of solving a simple
       Laplace problem using $hp$-adaptation and hybrid multigrid methods on machines