@article {IOPORT.06081330, author = {Pournin, Lionel}, title = {Lifting simplicial complexes to the boundary of convex polytopes.}, year = {2012}, journal = {Discrete Mathematics}, volume = {312}, number = {19}, issn = {0012-365X}, pages = {2849-2862}, publisher = {Elsevier Science B.V. (North-Holland), Amsterdam}, doi = {10.1016/j.disc.2012.06.005}, abstract = {Summary: A simplicial complex $C$ on a $d$-dimensional configuration of $n$ points is $k$-regular if its faces are projected from the boundary complex of a polytope with dimension at most $d+k$. Since $C$ is obviously $(n - d - 1)$-regular, the set of all integers $k$ for which $C$ is $k$-regular is non-empty. The minimum $\delta (C)$ of this set deserves attention because of its link with flip-graph connectivity. This paper introduces a characterization of $\delta (C)$ derived from the theory of Gale transforms. Using this characterization, it is proven that $\delta (C)$ is never greater than $n - d - 2$. Several new results on flip-graph connectivity follow. In particular, it is shown that connectedness does not always hold for the subgraph induced by 3-regular triangulations in the flip-graph of a point configuration.}, identifier = {06081330}, }