Abstract: The concept of perfection of a polytope was introduced by S. A. Robertson. Intuitively speaking, a polytope $P$ is perfect if and only if it cannot be deformed to a polytope of different shape without changing the action of its symmetry group $G(P)$ on its face-lattice $F(P)$. By Rostami's conjecture, the perfect 4-polytopes form a particular set of Wythoffian polytopes. In the present paper first this known set is briefly surveyed. In the rest of the paper 2 new classes of perfect 4-polytopes are constructed and discussed, hence Rostami's conjecture is disproved. It is emphasized that in contrast to an existing opinion in the literature, the classification of perfect 4-polytopes is not complete as yet.
Keywords: perfect polytope; Rostami conjecture; Wythoff polytopes; classification of perfect 4-polytopes
Classification (MSC2000): 52B15
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