Questions tagged [triangulation]
For questons about triangulation, that is a) the subdivision of the plane or other topological spaces into triangles (or, more generally, simplices) or b) the methods used in surveying for locating points by measuring angles and accessible lengths of triangles
495 questions
0 votes
0 answers
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References for triangulation of manifolds [closed]
I am writing because in our first course on differential geometry in Spain, our professor has decided to use the concept of triangulation to define integrals of n-forms on differential manifolds, but ...
3 votes
1 answer
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Is it possible to do trilateration with unspecified distance units?
Given an unknown point $P \in \mathbb{R}^2$, you can find its location if you have three known points $A$, $B$, and $C$ and distances $d(A,P) = a$, $d(B,P) = b$, and $d(C,P) = c$. If you're finding an ...
1 vote
0 answers
63 views
Triangulation of $RP^2$
This an exercise from Munkres' Algebraic Topology. Are figures 3.9 and 3.10 both triangualtions of $RP^2$, or is 3.10 different? (If yes, then it is deceptively simple). Is it so that only the ...
0 votes
0 answers
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Simplicial homology does not always count holes?
Consider a triangular region (2-cell). The boundary triangle (1-cell) is a boundary because it bounds the 2-cell in the sense that there exists a neighborhood that which belong to the 2-cell and ...
2 votes
1 answer
68 views
Does requiring that the triangles in a surface triangulation become small avoid the Schwartz lantern problem?
One possible approach to defining the surface area of a smooth 2D surface embedded into 3D Euclidean space, which is a natural generalization of the idea of calculating the arc length of a 1D curve as ...
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Triangulation of a manifold with curve as a subcomplex
Theorem 1.7 in "Curves on 2-manifolds and isotopies" by Epstein says that "If a simple closed curve $S$ on a surface $M$ is homotopic to zero, then it bounds a disk". At one point ...
4 votes
2 answers
542 views
Hauptvermutung for a ball
This question is probably known for any expert in geometric topology: Is it true that any two triangulations of the $d$-dimensional ball have a common refinement? As I've learned, this question is ...
0 votes
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N Dimensional Bistellar Flips
Is there some material on what are the N-Dimensional Bistellar Flips (Regarding Delaunay Triangulation)? At most I've found this material with the 4D Bistellar Flips: https://arxiv.org/pdf/2312....
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Graph invariant that differentiates torus triangulations with different Dehn twist
I'm looking at the simple, locally $C_6$ graphs (open neighbourhood of each vertex is $C_6$) with 16 vertices whose clique complex is a triangulation of a 2-torus (and not a Klein bottle). There are 4 ...
0 votes
0 answers
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Is this definition of 'biggest' simplicial complex from a graph well-posed?
I understand that every smooth manifold has a triangulation (into a simplicial complex). I understand that from every triangulation we can define the underlying graph (using the 1-skeleton). Is it a ...
1 vote
1 answer
106 views
Proof that number of polygon triangulations equals the catalan numbers.
I'm trying to derive the recurrence relation for the Catalan numbers using polygon triangulation, but the final result is off by 1 index and I can't find my mistake. Context for the proof can be seen ...
1 vote
0 answers
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Given any set of $3$D points, can we always tetrahedronize them?
Given any set of $3$D points, can we always make non-overlapping tetrahedrons from them where the union of tetrahedrons exactly fill the convex hull of the input points? AFAIK, given any set of $2$D ...
2 votes
1 answer
304 views
The simplicial homology of the real projective plane $\mathbb{RP}^2$
For my Topology I class, I had the following exercise: Find a triangulation of $\mathbb{RP}^2$ and draw it. Then, set up the chain complex $C_\bullet(K)$ and compute its homology groups. I should ...
9 votes
2 answers
830 views
Minimum Number of Triangles for Triangulation of Closed Surfaces
I am studying Topology, and recently I learned that every closed surface (2 dimensional manifold) can be triangulated. I understood triangulation as making polygons (with triangles) homeomorphic to ...
1 vote
1 answer
91 views
Triangulation of CW Complex Induces Triangulation of Closed Cells
Suppose $X$ is a CW complex (I use definition in Munkres, Elements of Algebraic Topology), $h:|K|\to X$ is a triangulation, i.e. $|K|$ is simplicial complex and $h$ homeomorphism. Supposed in addition ...