Abstract
We deal with mappings defined between Riemannian manifolds that belong to a trace space of Sobolev functions. The homological singularities of any such map are represented by a current defined in terms of the boundary of its graph. Under suitable topological assumptions on the domain and target manifolds, we show that the non triviality of the singular current is the only obstruction to the strong density of smooth maps. Moreover, we obtain an upper bound for the minimal integral connection of the singular current that depends on the fractional norm of the mapping.
Similar content being viewed by others
References
Adams R.A.: Sobolev Spaces. Academic Press, New York (1975)
Almgren, F.J., Browder, W., Lieb, E.H.: Co-area, liquid crystals, and minimal surfaces. In: Partial Differential Equations, Springer Lecture Notes in Math. 1306, 1–22 (1988)
Bethuel F.: A characterization of maps in \({H^1(B^3,\mathbb {S}^2)}\) which can be approximated by smooth maps. Ann. Inst. H. Poincaré Anal. Non Linéaire 7, 269–286 (1990)
Bethuel F.: Approximations in trace spaces defined between manifolds. Nonlinear Anal 24, 121–130 (1995)
Bethuel F., Demengel F.: Extensions for Sobolev mappings between manifolds. Calc. Var. Partial Differ. Equ. 3, 475–491 (1995)
Bourgain J., Brezis H., Mironescu P.: Lifting in Sobolev spaces. J. Anal. Math. 80, 37–86 (2000)
Bourgain J., Brezis H., Mironescu P.: On the structure of the Sobolev space H 1/2 with values into the circle. C.R. Acad. Sci. Paris 331, 119–124 (2000)
Bourgain J., Brezis H., Mironescu P.: H 1/2 maps with values into the circle: minimal connections, lifting, and the Ginzburg Landau equation. Publ. Math. Inst. Hautes Études Sci. 99, 1–115 (2004)
Bourgain J., Brezis H., Mironescu P.: Lifting, degree, and distributional Jacobian revisited. Comm. Pure Appl. Math. 58, 529–551 (2005)
Bousquet P.: Topological singularities in \({W^{s,p}(\mathbb {S}^N,\mathbb {S}^1)}\). J. Anal. Math. 102, 311–346 (2007)
Bousquet P.: Fractional Sobolev spaces and topology. Nonlinear Anal. 68, 804–827 (2008)
Brezis H., Li Y., Mironescu P., Nirenberg L.: Degree and Sobolev spaces. Topol. Methods Nonlinear Anal. 13, 181–190 (1999)
Brezis H., Mironescu P.: On some questions of topology for \({\mathbb {S}^1}\) -valued fractional Sobolev spaces. RACSAM Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. 95, 121–143 (2001)
Brezis H., Nirenberg L.: Degree theory and BMO. I. Compact manifolds without boundaries. Selecta Math. (N.S.) 1, 197–263 (1995)
Escobedo M.: Some remarks on the density of regular mappings in Sobolev classes of \({\mathbb {S}^M}\) -valued functions. Rev. Mat. Univ. Complut. Madrid 1, 127–144 (1988)
Federer H.: Geometric measure theory. Grundlehren math. wissen. 153. Springer, New York (1969)
Federer H.: Real flat chains, cochains and variational problems. Indiana Univ. Math. J. 24, 351–407 (1974)
Gagliardo E.: Caratterizzazione delle tracce sulla frontiera relative ad alcune classi di funzioni in n variabili. Rend. Sem. Mat. Univ. Padova 27, 284–305 (1957)
Giaquinta M., Modica G., Mucci D.: The relaxed Dirichlet energy of manifold constrained mappings. Adv. Calc. Var. 1, 1–51 (2008)
Giaquinta, M., Modica, G., Souček, J.: Cartesian currents in the calculus of variations, I, II. Ergebnisse Math. Grenzgebiete (III Ser), 37, 38. Springer, Berlin (1998)
Giaquinta M., Modica G., Souček J.: On sequences of maps into \({\mathbb {S}^1}\) with equibounded W 1/2 energies. Selecta Math. (N.S.) 10, 359–375 (2004)
Giaquinta M., Mucci D.: Density results for the W 1/2 energy of maps into a manifold. Math. Z. 251, 535–549 (2005)
Giaquinta M., Mucci D.: On sequences of maps into a manifold with equibounded W 1/2-energies. J. Funct. Anal. 225, 94–146 (2005)
Giaquinta, M., Mucci, D.: Maps into manifolds and currents: area and W 1,2-, W 1/2-, BV-energies. Edizioni della Normale, C.R.M. Series, Sc. Norm. Sup. Pisa (2006)
Hang F., Lin F.: A remark on the Jacobians. Comm. Contemp. Math. 2, 35–46 (2000)
Hang F., Lin F.: Topology of Sobolev mappings. II. Acta Math 191, 55–107 (2003)
Hardt R., Lin F.: Mappings minimizing the L p norm of the gradient. Comm. Pure Appl. Math. 40, 555–588 (1987)
Hardt, R., Pitts, J.: Solving the Plateau’s problem for hypersurfaces without the compactness theorem for integral currents. In: Allard, W.K., Almgren, F.J. (eds.) Geometric Measure Theory and the Calculus of Variations. Proc. Symp. Pure Math., Am. Math. Soc., Providence, 44, 255–295 (1996)
Hardt R., Rivière T.: Connecting topological Hopf singularities. Ann. Scuola Norm. Sup. Pisa Cl. Sci. (5) 2, 287–344 (2003)
Hardt R., Rivière T.: Connecting rational homotopy type singularities. Acta Math. 200, 15–83 (2008)
Hu S.T.: Homotopy theory. Academic press, New York (1959)
Isobe T.: Obstructions to the extension problem of Sobolev mappings. Topol. Methods Nonlinear Anal. 21, 345–368 (2003)
Kuwert E.: A compactness result for loops with an H 1/2-bound. J. Reine Angew. Math. 505, 1–22 (1998)
Millot V., Pisante A.: Relaxed energies for H 1/2-maps with values into the circle and measurable weights. Indiana Univ. Math. J. 58, 49–136 (2009)
Mironescu, P.: On some properties of \({\mathbb {S}^1}\) -valued fractional Sobolev spaces. In: Noncompact problems at the intersection of geometry, analysis, and topology, Contemp. Math., 350, Am. Math. Soc., Providence, RI, pp. 201–207 (2004)
Mironescu P., Pisante A.: A variational problem with lack of compactness for \({H^{1/2}(\mathbb {S}^1;\mathbb {S}^1)}\) maps of prescribed degree. J. Funct. Anal. 217, 249–279 (2004)
Morgan F.: Area minimizing currents bounded by multiples of curves. Rend. Circ. Mat. Palermo 33, 37–46 (1984)
Mucci D.: Strong density results in trace spaces of maps between manifolds. Manuscr. Math. 128(1), 421–441 (2009)
Müller T.: Compactness for maps minimizing the n-energy under a free boundary constraint. Manuscr. Math. 103, 513–540 (2000)
Pakzad M.R., Rivière T.: Weak density of smooth maps for the Dirichlet energy between manifolds. Geom. Funct. Anal. 13, 223–257 (2001)
Rivière T.: Dense subsets of \({H^{1/2}(\mathbb {S}^2;\mathbb {S}^1)}\). Ann. Glob. Anal. Geom. 18, 517–528 (2000)
Simon, L.: Lectures on geometric measure theory. In: Proceedings of the Centre for Math. Analysis, vol. 3 Australian National University, Canberra (1983)
White B.: The least area bounded by multiples of a curve. Proc. Am. Math. Soc. 90, 230–232 (1984)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Mucci, D. The homological singularities of maps in trace spaces between manifolds. Math. Z. 266, 817–849 (2010). https://doi.org/10.1007/s00209-009-0600-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00209-009-0600-1