Abstract
We study regularity properties of variational solutions to a class of Cauchy–Dirichlet problems of the form
{
∂
t
u
-
div
x
(
D
ξ
f
(
D
u
)
)
=
0
in
Ω
T
,
u
=
u
0
on
∂
𝒫
Ω
T
.
\left\{\begin{aligned} \displaystyle\partial_{t}u-\operatorname{div}_{x}(D_{%
\xi}f(Du))&\displaystyle=0&&\displaystyle\phantom{}\text{in }\Omega_{T},\\
\displaystyle u&\displaystyle=u_{0}&&\displaystyle\phantom{}\text{on }\partial%
_{\mathcal{P}}\Omega_{T}.\end{aligned}\right.
We do not impose any growth conditions from above on
f
:
ℝ
n
→
ℝ
{f\colon\mathbb{R}^{n}\to\mathbb{R}}
, but only require it to be convex and coercive. The domain
Ω
⊂
ℝ
n
{\Omega\subset\mathbb{R}^{n}}
is mainly supposed to be bounded and convex, and for the time-independent boundary datum
u
0
:
Ω
¯
→
ℝ
{u_{0}\colon\overline{\Omega}\to\mathbb{R}}
we only require continuity. These requirements are weaker than a one-sided bounded slope condition. We prove global continuity of the unique variational solution
u
:
Ω
T
→
ℝ
{u\colon\Omega_{T}\to\mathbb{R}}
. If the boundary datum is Lipschitz continuous, we obtain global Hölder continuity of the solution.