Analysis and Numerics of Some Fractal Boundary Value Problems
Abstract
We describe some recent results for boundary value problems with fractal boundaries. Our aim is to show that the numerical approach to boundary value problems, so much cherished and in many ways pioneering developed by Enrico Magenes, takes on a special relevance in the theory of boundary value problems in fractal domains and with fractal operators. In this theory, in fact, the discrete numerical analysis of the problem precedes, and indeed give rise to, the asymptotic continuous problem, reverting in a sense the process consisting in deriving discrete approximations from the PDE itself by finite differences or finite elements. As an illustration of this point, in this note we describe some recent results on: the approximation of a fractal Laplacian by singular elliptic partial differential operators, by Vivaldi and the author; the asymptotic of degenerate Laplace equations in domains with a fractal boundary, by Capitanelli-Vivaldi; the fast heat conduction on a Koch interface, by Lancia-Vernole and co-authors. We point out that this paper has an illustrative purpose only and does not aim at providing a survey on the subject.
Keywords
Spectral Measure Dirichlet Form Dirichlet Condition Transmission Problem Trace SpaceNotes
Acknowledgements
This work was supported by the NSF grant No. 1109356.
The author wishes to thank the authors of the papers presented in this note for their kindness in providing him with the preprints of their work.
The author wishes also to thank the Colleagues in Pavia who organized the Conference for their invitation and hospitality and the Editors of the Volume of the conference for the opportunity given to him of contributing this paper.
References
- 1.Achdou, Y., Sabot, C., Tchou, N.: A multiscale numerical method for Poisson problems in some ramified domains with fractal boundary. Multiscale Model. Simul. 5(3), 828–860 (2006) MathSciNetMATHCrossRefGoogle Scholar
- 2.Attouch, H.: Variational Convergence for Functions and Operators. Pitman, London (1984) MATHGoogle Scholar
- 3.Bagnerini, P., Buffa, A., Vacca, E.: Finite elements for a prefractal transmission problem. C. R. Math. 342(3), 211–214 (2006) MathSciNetMATHGoogle Scholar
- 4.Barlow, M.T., Hambly, B.M.: Transition density estimates for Brownian motion on scale irregular Sierpiński gaskets. Ann. Inst. Henri Poincaré 33(5), 531–557 (1997) MathSciNetMATHCrossRefGoogle Scholar
- 5.Cannon, J.R., Meyer, G.H.: On a diffusion in a fractured medium. SIAM J. Appl. Math. 3, 434–448 (1971) CrossRefGoogle Scholar
- 6.Capitanelli, R., Vivaldi, M.A.: Insulating layers and Robin problems on Koch mixtures. J. Differ. Equ. 251(4–5), 1332–1353 (2011) MathSciNetMATHCrossRefGoogle Scholar
- 7.Capitanelli, R., Vivaldi, M.A.: On the Laplacean transfer across a fractal mixture Asymptot. Anal. doi: 10.3233/ASY-2012-1149
- 8.Cefalo, M., Dell’Acqua, G., Lancia, M.R.: Numerical approximation of transmission problems across Koch-type highly conductive layers. Appl. Math. Comput. 218(9.1), 5453–5473 (2012) MathSciNetMATHGoogle Scholar
- 9.Cefalo, M., Lancia, M.R., Liang, H.: Heat flow problems across fractal mixtures: regularity results of the solutions and numerical approximation (to appear) Google Scholar
- 10.Evans, E.: Extension operators and finite elements for fractal boundary value problems. PhD thesis, Worcester Polytechnic Institute, USA (2011) Google Scholar
- 11.Grisvard, P.: Elliptic Problems in Nonsmooth Domains. Pitman, London (1985) MATHGoogle Scholar
- 12.Hutchinson, J.E.: Fractals and self-similarity. Indiana Univ. Math. J. 30, 713–747 (1981) MathSciNetMATHCrossRefGoogle Scholar
- 13.Jonsson, A.: Dirichlet forms and Brownian motion penetrating fractals. Potential Anal. 13, 69–80 (2000) MathSciNetMATHCrossRefGoogle Scholar
- 14.Jonsson, A., Wallin, H.: Function Spaces on Subsets of ℝn, Part 1. Math. Reports, vol. 2. Harwood Academic, London (1984) Google Scholar
- 15.Kuwae, K., Shioya, T.: Convergence of spectral structures: a functional analytic theory and its applications to spectral geometry. Commun. Anal. Geom. 11(4), 599–673 (2003) MathSciNetMATHGoogle Scholar
- 16.Lancia, M.R.: A transmission problem with a fractal interface. Z. Anal. Anwend. 21, 113–133 (2002) MathSciNetMATHGoogle Scholar
- 17.Lancia, M.R., Vacca, E.: Numerical approximation of heat flow problems across highly conductive layers. In: Silhavy, M. (ed.) Mathematical Modeling of Bodies with Complicated Bulk and Boundary Behaviour. Quaderni di Matematica, pp. 57–77. Dept. Me. Mo. Mat., U. Roma La Sapienza, Roma (2007) Google Scholar
- 18.Lancia, M.R., Vivaldi, M.A.: Asymptotic convergence for energy forms. Adv. Math. Sci. Appl. 13, 315–341 (2003) MathSciNetMATHGoogle Scholar
- 19.Lancia, M.R., Vernole, P.: Convergence results for parabolic transmission problems across highly conductive layers with small capacity. Adv. Math. Sci. Appl. 16, 411–445 (2006) MathSciNetMATHGoogle Scholar
- 20.Lancia, M.R., Vernole, P.: Irregular heat flow problems. SIAM J. Math. Anal. 42(4), 1539–1567 (2010) MathSciNetMATHCrossRefGoogle Scholar
- 21.Lancia, M.R., Vernole, P.: Semilinear evolution transmission problems across fractal layers. Nonlinear Anal., Theory Methods Appl. 75, 4222–4240 (2012) MathSciNetMATHCrossRefGoogle Scholar
- 22.Lancia, M.R., Vernole, P.: Semilinear fractal problems: Approximation and regularity results. Nonlinear Anal., Theory Methods Appl. Article first published online 2 Nov 2012. doi: 10.1016/j.na2012.08.020
- 23.Liang, H.: On the construction of certain fractal mixtures. MS Thesis, Worcester Polytechnic Institute (2010) Google Scholar
- 24.Mosco, U.: Composite media and asymptotic Dirichlet forms. J. Funct. Anal. 123(2), 368–421 (1994) MathSciNetMATHCrossRefGoogle Scholar
- 25.Mosco, U.: Variational fractals. Ann. Sc. Norm. Super. Pisa, Cl. Sci. (4) XXV, 683–712 (1997) MathSciNetGoogle Scholar
- 26.Mosco, U.: Harnack inequalities on scale irregular Sierpiński gaskets. In: Birman, et al. (eds.) Nonlinear Problems in Mathematical Physics and Related Topics II, pp. 305–328. Kluwer Academic/Plenum, New York (2002) CrossRefGoogle Scholar
- 27.Mosco, U., Vivaldi, M.A.: An example of fractal singular homogenization. Georgian Math. J. 14(1), 169–194 (2007) MathSciNetMATHGoogle Scholar
- 28.Mosco, U., Vivaldi, M.A.: Fractal reinforcement of elastic membranes. Arch. Ration. Mech. Anal. 194, 49–74 (2009) MathSciNetMATHCrossRefGoogle Scholar
- 29.Mosco, U., Vivaldi, M.A.: Vanishing viscosity for fractal sets. Discrete Contin. Dyn. Syst. 28(3), 1207–1235 (2010) MathSciNetMATHCrossRefGoogle Scholar
- 30.Mosco, U., Vivaldi, M.A.: Thin fractal fibers. Math. Methods Appl. Sci. Article first published online 14 Jun 2012. doi: 10.1002/mma.1621
- 31.Pham Huy, H., Sanchez Palencia, E.: Phénomènes des transmission à travers des couches minces de conductivité élevée. J. Math. Anal. Appl. 47, 284–309 (1974) MathSciNetMATHCrossRefGoogle Scholar
- 32.Vacca, E.: Galerkin approximation for highly conductive layers. PhD Thesis, Dept. Me. Mo. Mat., U. Roma La Sapienza (2005) Google Scholar
- 33.Wasyk, R.: Numerical solution of a transmission problem with pre fractal interface. PhD Thesis, Worcester Polytechnic Institute (2007) Google Scholar