An infinite family of tight triangulations of manifolds
نویسندگان
چکیده
We give explicit construction of vertex-transitive tight triangulations of d-manifolds for d ≥ 2. More explicitly, for each d ≥ 2, we construct two (d + 5d + 5)-vertex neighborly triangulated d-manifolds whose vertex-links are stacked spheres. The only other non-trivial series of such tight triangulated manifolds currently known is the series of non-simply connected triangulated d-manifolds with 2d + 3 vertices constructed by Kühnel. The manifolds we construct are strongly minimal. For d ≥ 3, they are also tight neighborly as defined by Lutz, Sulanke and Swartz. Like Kühnel’s complexes, our manifolds are orientable in even dimensions and non-orientable in odd dimensions. MSC 2000 : 57Q15, 57R05.
منابع مشابه
Tight and stacked triangulations of manifolds
Tight triangulated manifolds are generalisations of neighborly triangulations of closed surfaces and are interesting objects in Combinatorial Topology. Tight triangulated manifolds are conjectured to be minimal. Except few, all the known tight triangulated manifolds are stacked. It is known that locally stacked tight triangulated manifolds are strongly minimal. Except for three infinite series ...
متن کاملCoverings and minimal triangulations of 3–manifolds
Given a closed, irreducible 3–manifold, its complexity is the minimum number of tetrahedra in a (pseudosimplicial) triangulation of the manifold. This number agrees with the complexity defined by Matveev [5] unless the manifold is S , RP or L.3; 1/. The complexity for an infinite family of closed manifolds has first been given by the authors in [4]. The family consisted of lens spaces having a ...
متن کاملTight Combinatorial Manifolds and Graded Betti Numbers
In this paper, we study the conjecture of Kühnel and Lutz, who state that a combinatorial triangulation of the product of two spheres S×S with j ≥ i is tight if and only if it has exactly i+2j+4 vertices. To approach this conjecture, we use graded Betti numbers of Stanley–Reisner rings. By using recent results on graded Betti numbers, we prove that the only if part of the conjecture holds when ...
متن کاملTight triangulations of some 4-manifolds
Walkup’s class K(d) consists of the d-dimensional simplicial complexes all whose vertex links are stacked (d − 1)-spheres. According to a result of Walkup, the face vector of any triangulated 4-manifold X with Euler characteristic χ satisfies f1 ≥ 5f0 − 15 2 χ, with equality only for X ∈ K(4). Kühnel observed that this implies f0(f0− 11) ≥ −15χ, with equality only for 2-neighborly members of K(...
متن کاملStructures of small closed non-orientable 3-manifold triangulations
A census is presented of all closed non-orientable 3-manifold triangulations formed from at most seven tetrahedra satisfying the additional constraints of minimality and P-irreducibility. The eight different 3-manifolds represented by these 41 different triangulations are identified and described in detail, with particular attention paid to the recurring combinatorial structures that are shared...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- J. Comb. Theory, Ser. A
دوره 120 شماره
صفحات -
تاریخ انتشار 2013