TITLE: Bernstein type theorems for CMC hypersurfaces in $\mathbb{R}^{n+1}$
QUESTION [5 upvotes]: Is there any Bernstein type theorems for CMC hypersurfaces in $\mathbb{R}^{n+1}$ in the literature? 
More precisely I would like to know if there is an answer to the following
QUESTION: Let $f : \mathbb{R}^n \to \mathbb{R}$ be a smooth function such that $\mathrm{graph}(f)$ is a constant mean curvature hypersurface of $\mathbb{R}^{n+1}$. Is it true that $\mathrm{graph}(f)$ must be an affine hyperplane? 
I don't know much about CMC hypersurfaces and I don't know where to look for an answer. Even if the question has a negative answer, I would like to know if there are counterexamples or if one can get an affirmative answer under some volume growth condition. 
Any help will be very much appreciated! 
Thanks!

REPLY [7 votes]: This was solved in a series of articles in the 1960s.
De Giorgi, Almgren, and Simons have shown that in $\mathbb{R}^{\le 8}$ every CMC graph is a hyperplane. Then Bombieri - De Giorgi - Giusti have shown that in $\mathbb{R}^{\ge 9}$ there are minimal graphs which are not hyperplanes.
Here is a link to the latter article:
Bombieri, E.; De Giorgi, E.; Giusti, E., Minimal cones and the Bernstein problem, Invent. Math. 7, 243-268 (1969). ZBL0183.25901.