Please wait a minute...
Frontiers of Mathematics in China

ISSN 1673-3452

ISSN 1673-3576(Online)

CN 11-5739/O1

Postal Subscription Code 80-964

2018 Impact Factor: 0.565

Front. Math. China    2016, Vol. 11 Issue (5) : 1345-1362    https://doi.org/10.1007/s11464-016-0575-2
RESEARCH ARTICLE
On combinatorial Gauss-Bonnet Theorem for general Euclidean simplicial complexes
Stephan KLAUS()
Scientific Administrator of the MFO and Adjunct Professor at Mainz University, Mathematisches Forschungsinstitut Oberwolfach gGmbH (MFO), Schwarzwaldstrasse 9-11, D-77709 Oberwolfach-Walke, Germany
 Download: PDF(191 KB)  
 Export: BibTeX | EndNote | Reference Manager | ProCite | RefWorks
Abstract

For a finitely triangulated closed surface M2, let αx be the sum of angles at a vertex x. By the well-known combinatorial version of the 2-dimensional Gauss-Bonnet Theorem, it holds x(2π−αx) = 2πχ(M2), where χ denotes the Euler characteristic of M2, αx denotes the sum of angles at the vertex x, and the sum is over all vertices of the triangulation. We give here an elementary proof of a straightforward higher-dimensional generalization to Euclidean simplicial complexes K without assuming any combinatorial manifold condition. First, we recall some facts on simplicial complexes, the Euler characteristics and its local version at a vertex. Then we define δ(τ) as the normed dihedral angle defect around a simplexτ. Our main result is ∑τ (−1)dim(τ)δ(τ) =χ(K), where the sum is over all simplices τ of the triangulation. Then we give a definition of curvature κ(x) at a vertex and we prove the vertex-version xK0κ(x) =χ(K) of this result. It also possible to prove Morse-type inequalities. Moreover, we can apply this result to combinatorial (n + 1)-manifolds W with boundary B, where we prove that the difference of Euler characteristics is given by the sum of curvatures over the interior of W plus a contribution from the normal curvature along the boundary B:χ(W) −12χ(B) = τWB(−1)dim(τ)δ(τ) +τB(−1)dim(τ)ρ(τ).

Keywords Curvature      dihedral angle      Euclidean simplex      triangulation      Euler characteristic      Euler manifold      combinatorial manifold      pseudo manifold     
Corresponding Author(s): Stephan KLAUS   
Issue Date: 23 September 2016
 Cite this article:   
Stephan KLAUS. On combinatorial Gauss-Bonnet Theorem for general Euclidean simplicial complexes[J]. Front. Math. China, 2016, 11(5): 1345-1362.
 URL:  
https://academic.hep.com.cn/fmc/EN/10.1007/s11464-016-0575-2
https://academic.hep.com.cn/fmc/EN/Y2016/V11/I5/1345
1 Allendoerfer C B, Weil A. The Gauss-Bonnet Theorem for Riemannian polyhedra. Trans Amer Math Soc, 1943, 53: 101–129
https://doi.org/10.1090/S0002-9947-1943-0007627-9
2 Banchoff T F. Critical points and curvature for embedded polyhedra. J Differential Geom, 1967, 1: 245–256
3 Banchoff T F. Critical points and curvature for embedded polyhedral surfaces. Amer Math Monthly, 1970, 77: 475–485
https://doi.org/10.2307/2317380
4 Banchoff T F. Critical points and curvature for embedded polyhedra. II. In: Differential Geometry (College Park, Md, 1981/1982). Progr Math, Vol 32. Boston: Birkhäuser, 1983, 34–55
5 Berger M. Geometry I. Berlin: Springer, 1987
https://doi.org/10.1007/978-3-540-93815-6
6 Bloch E D. The angle defect for arbitrary polyhedra. Beiträge Algebra Geom, 1998, 39: 379–393
7 Bloch E D. Critical points and the angle defect. Geom Dedicata, 2004, 109: 121–137
https://doi.org/10.1007/s10711-004-2385-z
8 Bloch E D. The angle defect for odd-dimensional simplicial manifolds. Discrete Comput Geom, 2006, 35(2): 311–328
https://doi.org/10.1007/s00454-005-1221-z
9 Chern S S. A simple intrinsic proof of the Gauss-Bonnet formula for closed Riemannian manifolds, Ann of Math, 1944, 45: 747–752
https://doi.org/10.2307/1969302
10 Conway J H, Guy R K. The Book of Numbers. Berlin: Springer, 1996, 107–109
https://doi.org/10.1007/978-1-4612-4072-3
11 Hopf H. Differential Geometry in the Large. Lecture Notes in Math, Vol 1000. Berlin: Springer, 1989
https://doi.org/10.1007/3-540-39482-6
12 Klee V. A combinatorial analogue of Poincaré’s duality theorem. Canad J Math, 1964, 16: 517–531
https://doi.org/10.4153/CJM-1964-053-0
13 Levitt N. The Euler characteristic is the unique locally determined numerical homotopy invariant of finite complexes. Discrete Comput Geom, 1992, 7(1): 59–67
https://doi.org/10.1007/BF02187824
14 MacLaurin C, Robertson G. Euler characteristic in odd dimensions. Austral Math Soc Gaz, 2003, 30(4): 195–199
15 Milnor J W, Stasheff J D. Characteristic Classes. Ann of Math Stud, Vol 76. Princeton: Princeton Univ Press, 1974
16 Murakami J. Volume formulas for a spherical tetrahedron. Proc Amer Math Soc, 2012, 140(9): 3289–3295
https://doi.org/10.1090/S0002-9939-2012-11182-7
17 Rourke C, Sanderson B. Introduction to Piecewise-Linear Topology. Berlin: Springer, 1982
18 Spanier E H. Algebraic Topology. Berlin: Springer, 1966
19 Wall C T C. Arithmetic invariants of subdivision of complexes. Canad J Math, 1966, 18: 92–96
https://doi.org/10.4153/CJM-1966-012-9
20 Wu H-H. Historical development of the Gauss-Bonnet Theorem. Sci China Ser A, 2008, 51(4): 777–784
https://doi.org/10.1007/s11425-008-0029-8
[1] Ming LI, Lihong ZHANG. Properties of Berwald scalar curvature[J]. Front. Math. China, 2020, 15(6): 1143-1153.
[2] Yuxiang LI, Hongyan TANG. Remark on Gauss curvature equations on punctured disk[J]. Front. Math. China, 2020, 15(4): 701-707.
[3] Xiaochun RONG, Xuchao YAO. A generalized π2-diffeomorphism finiteness theorem[J]. Front. Math. China, 2020, 15(2): 399-418.
[4] Yonghong HUANG, Shanzhong SUN. Non-embedding theorems of nilpotent Lie groups and sub-Riemannian manifolds[J]. Front. Math. China, 2020, 15(1): 91-114.
[5] Hongzhi HUANG. Fibrations and stability for compact group actions on manifolds with local bounded Ricci covering geometry[J]. Front. Math. China, 2020, 15(1): 69-89.
[6] Xiaoxiang JIAO, Hong LI. Conformal minimal immersions with constant curvature from S2 to Q5[J]. Front. Math. China, 2019, 14(2): 315-348.
[7] Zonglin JI, Boling GUO. Landau-Lifshitz-Bloch equation on Riemannian manifold[J]. Front. Math. China, 2019, 14(1): 45-76.
[8] Xiaole SU, Hongwei SUN, Yusheng WANG. An isometrical CPn-theorem[J]. Front. Math. China, 2018, 13(2): 367-398.
[9] Songting YIN. Comparison theorems on Finsler manifolds with weighted Ricci curvature bounded below[J]. Front. Math. China, 2018, 13(2): 435-448.
[10] Meng MENG, Shijin ZHANG. De Lellis-Topping type inequalities on smooth metric measure spaces[J]. Front. Math. China, 2018, 13(1): 147-160.
[11] Hongchuan XIA,Chunping ZHONG. A class of metrics and foliations on tangent bundle of Finsler manifolds[J]. Front. Math. China, 2017, 12(2): 417-439.
[12] Yi LI. Long time existence of Ricci-harmonic flow[J]. Front. Math. China, 2016, 11(5): 1313-1334.
[13] Mijia LAI. Metric aspects of conic surfaces[J]. Front. Math. China, 2016, 11(5): 1291-1312.
[14] Bobo HUA,Yong LIN. Curvature notions on graphs[J]. Front. Math. China, 2016, 11(5): 1275-1290.
[15] Martin HERRMANN. Almost nonnegative curvature operator and cohomology rings[J]. Front. Math. China, 2016, 11(5): 1259-1274.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed