Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-26T08:53:42.256Z Has data issue: false hasContentIssue false

Computing harmonic maps between Riemannian manifolds

Published online by Cambridge University Press:  18 February 2022

Jonah Gaster
Affiliation:
Department of Mathematical Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA e-mail: gaster@uwm.edu
Brice Loustau*
Affiliation:
Mathematisches Institut, Heidelberg University, Heidelberg, Germany Heidelberg Institute of Theoretical Studies (HITS), Heidelberg University, Heidelberg, Germany
Léonard Monsaingeon
Affiliation:
Institut Élie Cartan de Lorraine and Grupo de Física Matemática, IECL Université de Lorraine, Vandœuvre-lès-Nancy Cedex, France GFM Universidade de Lisboa, Lisboa, Portugal e-mail: leonard.monsaingeon@univ-lorraine.fr

Abstract

In our previous paper (Gaster et al., 2018, arXiv:1810.11932), we showed that the theory of harmonic maps between Riemannian manifolds, especially hyperbolic surfaces, may be discretized by introducing a triangulation of the domain manifold with independent vertex and edge weights. In the present paper, we study convergence of the discrete theory back to the smooth theory when taking finer and finer triangulations, in the general Riemannian setting. We present suitable conditions on the weighted triangulations that ensure convergence of discrete harmonic maps to smooth harmonic maps, introducing the notion of (almost) asymptotically Laplacian weights, and we offer a systematic method to construct such weighted triangulations in the two-dimensional case. Our computer software Harmony successfully implements these methods to compute equivariant harmonic maps in the hyperbolic plane.

Type
Article
Copyright
© Canadian Mathematical Society, 2022

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

The first two authors gratefully acknowledge support from NSF Grant DMS1107367 RNMS: GEometric structures And Representation varieties (the GEAR Network). The third author was partially supported by the Portuguese Science Foundation FCT trough grant PTDC/MAT-STA/0975/2014 from Stochastic Geometric Mechanics to Mass Transportation Problems.

References

Bartels, S., Numerical analysis of a finite element scheme for the approximation of harmonic maps into surfaces. Math. Comp. 79(2010), no. 271, 12631301.CrossRefGoogle Scholar
Bobenko, A. I. and Springborn, B. A., A discrete Laplace-Beltrami operator for simplicial surfaces. Discrete Comput. Geom. 38(2007), no. 4, 740756.CrossRefGoogle Scholar
Brunck, F., Iterated medial triangle subdivision in surfaces of constant curvature. Preprint, 2021. arXiv:2107.04112Google Scholar
Crane, K., The $n$ -dimensional cotangent formula. 2019. https://www.cs.cmu.edu/~kmcrane/Projects/Other/nDCotanFormula.pdf Google Scholar
de Saint-Gervais, H.-P., Approximation d’objets lisses par des objets PL. 2014–2019. http://analysis-situs.math.cnrs.fr/Approximation-d-objets-lisses-par-des-objets-PL.html Google Scholar
Eells, J. and Fuglede, B., Harmonic maps between Riemannian polyhedra, Cambridge Tracts in Mathematics, 142, Cambridge University Press, Cambridge, 2001. With a preface by M. Gromov.Google Scholar
Eells, J. Jr. and Sampson, J. H., Harmonic mappings of Riemannian manifolds. Amer. J. Math. 86(1964), 109160.CrossRefGoogle Scholar
Gaster, J., Loustau, B., and Monsaingeon, L., Computing discrete equivariant harmonic maps. Preprint, 2018. arXiv:1810.11932 Google Scholar
Hartman, P., On homotopic harmonic maps. Canad. J. Math. 19(1967), 673687.CrossRefGoogle Scholar
Jost, J.. Harmonic mappings between Riemannian manifolds, Proceedings of the Centre for Mathematical Analysis, 4, Australian National University, Centre for Mathematical Analysis, Canberra, 1984.Google Scholar
Korevaar, N. J. and Schoen, R. M., Global existence theorems for harmonic maps to non-locally compact spaces. Comm. Anal. Geom. 5(1997), no. 2, 333387.CrossRefGoogle Scholar
Loustau, B., Harmonic maps from Kähler manifolds. Preprint, 2019.Google Scholar
Pinkall, U. and Polthier, K., Computing discrete minimal surfaces and their conjugates. Exp. Math. 2(1993), no. 1, 1536.CrossRefGoogle Scholar
Riemann, B., Bernhard Riemann “Über die Hypothesen, welche der Geometrie zu Grunde liegen”, Klassische Texte der Wissenschaft [Classical Texts of Science], Springer Spektrum, Berlin, Heidelberg, 2013. Historical and mathematical commentary by Jürgen Jost.CrossRefGoogle Scholar
Zamfirescu, C. T., Survey of two-dimensional acute triangulations. Discrete Math. 313(2013), no. 1, 3549.CrossRefGoogle Scholar