On Sobolev spaces and density theorems on Finsler manifolds

Document Type : Original Article

Authors

Department of Mathematics and Computer Science, Amirkabir University of Technology, 424, Hafez Ave., Tehran 15914, Iran

Abstract

Here, a natural extension of Sobolev spaces is defined for a Finsler structure F and it is shown that the set of all real C functions with compact support on a forward geodesically complete Finsler manifold (M,F), is dense in the extended Sobolev space H1p(M). As a consequence, the weak solutions u of the Dirichlet equation Δu=f can be approximated by C functions with compact support on M. Moreover, let WM be a regular domain with the Cr boundary W, then the set of all real functions in Cr(W)C0(W) is dense in Hkp(W), where kr. Finally, several examples are illustrated and sharpness of the inequality kr is shown.

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[1] R. Adams, Sobolev spaces, Academic press, New York, 1975.
[2] H. Akbar-Zadeh, Initiation to Global Finslerian Geometry, North- Holland Mathematical Library, 2006.
[3] T. Aubin, Some nonlinear problems in Riemannian geometry, Springer-Verlag, 1988.
[4] S. Azami, A. Razavi, Existence and uniqueness for a solution of Ricci flow on Finsler manifolds, Int. J. of Geom. Meth. in Mod. Phy., 10(3) (2013) 1-21.
[5] D. Bao, S. S. Chern, Z. Shen, Riemann-Finsler geometry, Springer-Verlag, 2000.
[6] D. Bao, B. Lackey, A Hodge decomposition theorem for Finsler spaces, C. R. Acad. Sci. Paris S´er. I Math., 323(1) (1996) 51-56.
[7] B. Bidabad, On compact Finsler spaces of positive constant curvature C. R. Acad. Sci. Paris S´er. I Math., 349 (2011) 1191-1194.
[8] B. Bidabad, A. Shahi, Harmonic vector fields on Finsler manifolds, C. R. Acad. Sci. Paris S´er. I Math., 354 (2016) 101-106.
[9] B. Bidabad, A. Shahi, M. Yar Ahmadi, Deformation of Cartan curvature on Finsler manifolds, Bull. Korean Math. Soc. 54(6) (2017) 2119-2139.
[10] B. Bidabad, M. Yar Ahmadi, Convergence of Finslerian metrics under Ricci flow, Sci. China Math. 59(4) (2016) 741-750.
[11] Y. Ge, Z. Shen, Eigenvalues, and eigenfunctions of metric measure manifolds, Proc. London Math. Soc., 82(3) (2001) 725-746.
[12] Q. He, Y. Shen, On Bernstein type theorems in Finsler spaces with the volume form induced from the projective sphere bundle, Proc. Amer. Math. Soc., 134(3) (2006) 871-880.
[13] M. Jim´enez-Sevilla, L. Sanchez-Gonzalez, On some problems on smooth approximation and smooth extension of Lipschitz functions on Banach-Finsler manifolds, Nonlinear Anal. 74(11) (2011) 3487-3500.
[14] A. Krist´aly, I. Rudas, Elliptic problems on the ball endowed with Funk-type metrics, Nonlinear Anal., 119 (2015) 199-208.
[15] S. Lakzian, Differential Harnack estimates for positive solutions to heat equation under Finsler-Ricci flow, Pacific J. Math., 278(2) (2015) 447-462
[16] H. Mosel, S. Winkelmann, On weakly harmonic maps from Finsler to Riemannian manifolds, Ann. I. H. Poincar´e, 26 (2009) 39-57.
[17] S. B. Myers, Algebras of differentiable functions, Proc. Amer. Math. Soc., 5 (1954) 917-922.
[18] S. Ohta, Nonlinear geometric analysis on Finsler manifolds, European Journal of Math., 3(4) (2017) 916-952.
[19] Z. Shen, Lectures on Finsler geometry, World Scientific, 2001.
[20] N. Winter, On the distance function to the cut locus of a submanifold in Finsler geometry, Ph.D. thesis, RWTH Aachen University, (2010).
[21] Y. Yang, Solvability of some elliptic equations on Finsler manifolds, math.pku.edu.cn preprint, 1-12.