Abstract
We present a \(2\times 2\) Lax representation for discrete circular nets of constant negative Gauß curvature. It is tightly linked to the 4D consistency of the Lax representation of discrete K-nets (in asymptotic line parametrization). The description gives rise to Bäcklund transformations and an associated family. All the members of that family—although no longer circular—can be shown to have constant Gauß curvature as well. Explicit solutions for the Bäcklund transformations of the vacuum (in particular Dini’s surfaces and breather solutions) and their respective associated families are given.











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Notes
For more general edge-bipartite graphs, vertices with valence greater than four might not have a continuous limit in the classical sense. For example, if the quad net is a discrete constant negative Gauß curvature surface parametrized by curvature lines, then these points are something like “Lorentz umbilics” [13].
References
Bobenko, A.I.: Surfaces in terms of 2 by 2 matrices: old and new integrable cases. In: Fordy, A.P., Wood, J.C. (eds.) Harmonic Maps and Integrable Systems, pp. 83–129. Vieweg, Braunschweig/Wiesbaden (1994)
Bobenko, A.I., Pinkall, U.: Discrete isothermic surfaces. J. Reine Angew. Math. 475, 187–208 (1996)
Bobenko, A.I., Pinkall, U.: Discrete surfaces with constant negative Gaussian curvature and the Hirota equation. J. Differ. Geom. 43, 527–611 (1996)
Bobenko, A.I., Pinkall, U.: Discretization of surfaces and integrable systems. In: Bobenko, A.I., Seiler, R. (eds.) Discrete Integrable Geometry and Physics, pp. 3–58. Oxford University Press, Oxford (1999)
Bobenko, A.I., Pottmann, H., Wallner, J.: A curvature theory for discrete surfaces based on mesh parallelity. Math. Ann. 348(1), 1–24 (2010)
Bobenko, A.I., Suris, Y.B.: Integrable systems on quad-graphs. Int. Math. Res. Not. 2002(11), 573–611 (2002)
Bobenko, A.I., Suris, Y.B.: Discrete Differential Geometry: Integrable Structure. Graduate Studies in Mathematics, vol. 98. American Mathematical Society, Providence (2008)
Cieśliński, J.: The spectral interpretation of \(n\)-spaces of constant negative curvature immersed in \(\mathbb{R}^{2n-1}\). Phys. Lett. A 236(5–6), 425–430 (1997)
Cieśliński, J.L.: Pseudospherical surfaces on time scales: a geometric definition and the spectral approach. J. Phys. A, Math. Theor. 40(42), 12525–12538 (2007)
Cieśliński, J., Doliwa, A., Santini, P.M.: The integrable discrete analogues of orthogonal coordinate systems are multi-dimensional circular lattices. Phys. Lett. A 235(5), 480–488 (1997)
Doliwa, A., Nieszporski, M.: Darboux transformations for linear operators on two-dimensional regular lattices. J. Phys. A, Math. Theor. 42(45), 454001 (2009)
Doliwa, A., Nieszporski, M., Santini, P.M.: Asymptotic lattices and their integrable reductions: I. The Bianchi–Ernst and the Fubini–Ragazzi lattices. J. Phys. A, Math. Gen. 34(48), 10–423 (2001)
Dorfmeister, J.F., Ivey, T., Sterling, I.: Symmetric pseudospherical surfaces I: general theory. Result. Math. 56(1–4), 3–21 (2009)
Hertrich-Jeromin, U., Hoffmann, T., Pinkall, U.: A discrete version of the Darboux transform for isothermic surfaces. In: Bobenko, A.I., Seiler, R. (eds.) Discrete Integrable Geometry and Physics, pp. 59–81. Oxford University Press, Oxford (1999)
Hirota, R.: Nonlinear partial difference equations III: discrete sine-Gordon equation. J. Phys. Soc. Japan 43(6), 2079–2086 (1977)
Hoffmann, T.: Discrete Amsler surfaces and a discrete Painlevé III equation. In: Bobenko, A.I., Seiler, R. (eds.) Discrete Integrable Geometry and Physics, pp. 83–96. Oxford University Press, Oxford (1999)
Hoffmann, T.: Discrete Hashimoto surfaces and a doubly discrete smoke-ring flow. In: Bobenko, A.I., Sullivan, J.M., Schröder, P., Ziegler, G.M. (eds.) Discrete Differential Geometry, pp. 95–115. Springer, Berlin (2008)
Hoffmann, T., Sageman-Furnas, A.O., Wardetzky, M.: A discrete parametrized surface theory in \(\mathbb{R}^3\). arXiv:1412.7293v1, preprint (2014)
Konopelchenko, B.G., Schief, W.K.: Trapezoidal discrete surfaces: geometry and integrability. J. Geom. Phys. 31(2), 75–95 (1999)
Nimmo, J.J.C., Schief, W.K.: Superposition principles associated with the Moutard transformation: an integrable discretization of a (2+1)-dimensional sine-Gordon system. Proc. R. Soc. A, Math. Phys. Eng. Sci. 453(1957), 255–279 (1997)
Pinkall, U.: Designing cylinders with constant negative curvature. In: Bobenko, A.I., Schröder, P., Sullivan, J.M., Ziegler, G.M. (eds.) Discrete Differential Geometry, pp. 57–66. Springer, Berlin (2008)
Rogers, C., Schief, W.K.: Bäcklund and Darboux Transformations: Geometry and Modern Applications in Soliton Theory. Cambridge Texts in Applied Mathematics. Cambridge University Press, Cambridge (2002)
Sauer, R.: Parallelogrammgitter als Modelle pseudosphärischer Flächen. Math. Z. 52(1), 611–622 (1950)
Schief, W.K.: On the unification of classical and novel integrable surfaces. II. Difference geometry. Proc. R. Soc. Lond., Ser. A, Math. Phys. Eng. Sci. 459(2030), 373–391 (2003)
Schief, W.K.: On a maximum principle for minimal surfaces and their integrable discrete counterparts. J. Geom. Phys. 56(9), 1484–1495 (2006)
Sym, A.: Soliton surfaces and their applications (soliton geometry from spectral problems). Geometric Aspects of the Einstein Equations and Integrable Systems. Lecture Notes in Physics, pp. 154–231. Springer, Berlin (1985)
Wunderlich, W.: Zur Differenzengeometrie der Flächen konstanter negativer Krümmung. Springer, Berlin (1951)
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T.H. was supported by the DFG-Collaborative Research Center, TRR 109, “Discretization in Geometry and Dynamics.”
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Hoffmann, T., Sageman-Furnas, A.O. A \(2\times 2\) Lax Representation, Associated Family, and Bäcklund Transformation for Circular K-Nets. Discrete Comput Geom 56, 472–501 (2016). https://doi.org/10.1007/s00454-016-9802-6
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DOI: https://doi.org/10.1007/s00454-016-9802-6
Keywords
- Discrete differential geometry
- Discrete integrable systems
- Bäcklund transformations
- Multidimensional consistency