Abstract
In the cases where there is no Sobolev-type or Gagliardo–Nirenberg-type fractional estimate involving \({|u |}_{W^{s,p}}\), we establish alternative estimates where the strong \(L^p\) norms are replaced by Lorentz norms.
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Bourgain, J., Brezis, H., Mironescu, P.: Lifting in Sobolev spaces. J. Anal. Math. 80(37–86), 0021–7670 (2000). https://doi.org/10.1007/BF02791533
Bourgain, J., Brezis, H., Mironescu, P.: Another look at Sobolev spaces, in Optimal Control and Partial Differential Equations, IOS, Amsterdam, pp. 439–455 (2001)
Brezis, H.: How to recognize constant functions. A connection with Sobolev spaces. Uspekhi Mat. Nauk. 57(4), 59–74 (2002); Russian Math. Surv. 57(4), 693–708 (2002). https://doi.org/10.1070/RM2002v057n04ABEH000533
Brezis, H.: Functional analysis, Sobolev spaces and partial differential equations. Universitext, Springer, New York (2011)
Brezis, H., Mironescu, P.: Gagliardo–Nirenberg inequalities and non-inequalities: the full story. Ann. Inst. H. Poincaré Anal. Non Linéaire 35(5), 1355–1376 (2018). https://doi.org/10.1016/j.anihpc.2017.11.007
Brezis, H., Van Schaftingen, J., Yung, P.-L.: A surprising formula for Sobolev norms. Proc. Natl. Acad. Sci. USA 118(8), e2025254118 (2021). https://doi.org/10.1073/pnas.2025254118
Brezis, H., Van Schaftingen, J., Yung, P.-L.: A surprising formula for Sobolev norms and related topics. arXiv:2003.05216v4
Castillo, R.E., Rafeiro, H.: An introductory course in Lebesgue spaces, CMS Books in Mathematics. Springer, Cham (2016)
Cohen, A., Dahmen, W., Daubechies, I., DeVore, R.: Harmonic analysis of the space BV. Rev. Mat. Iberoam. 19(1), 235–263 (2003). https://doi.org/10.4171/RMI/345
De Marco, G., Mariconda, C., Solimini, S.: An elementary proof of a characterization of constant functions. Adv. Nonlinear Stud. 8(3), 597–602 (2008). https://doi.org/10.1515/ans-2008-0306
fedja (https://math.stackexchange.com/users/12992/fedja). If \(\int _{\mathbb{R}^2} \frac{\vert f(x)-f(y)\vert }{\vert x-y\vert ^2} dxdy < \infty \) then \(f\) is a.e. constant. https://math.stackexchange.com/questions/488780 (version: 2013-10-30)
Figalli, A., Jerison, D.: How to recognize convexity of a set from its marginals. J. Funct. Anal. 266(3), 1685–1701 (2014). https://doi.org/10.1016/j.jfa.2013.05.040
Figalli, A., Serra, J.: On stable solutions for boundary reactions: a De Giorgi-type result in dimension \(4+1\). Invent. Math. 219(1), 153–177 (2020). https://doi.org/10.1007/s00222-019-00904-2
Gui, C., Li, Q.: Some energy estimates for stable solutions to fractional Allen–Cahn equations. Calc. Var. Partial Differ. Equ. (2020). https://doi.org/10.1007/s00526-020-1701-2
Grafakos, L.: Classical Fourier analysis, 3rd edn. Graduate Texts in Mathematics, vol. 249. Springer, New York (2014)
Greco, L., Schiattarella, R.: An embedding theorem for BV-functions. Commun. Contemp. Math. (1997) https://doi.org/10.1142/S0219199719500329
Hunt, R.A.: On \(L(p, q)\) spaces. Enseign. Math. (2) 12, 249–276 (1966)
O’Neil, R.: Convolution operators and \(L(p,\, q)\) spaces. Duke Math. J. 30(129–142), 0012–7094 (1963)
Poliakovsky, A.: Some remarks on a formula for Sobolev norms due to Brezis, Van Schaftingen and Yung. arXiv:2102.00557
Ranjbar-Motlagh, A.: A remark on the Bourgain–Brezis–Mironescu characterization of constant functions. Houston J. Math. 46(1), 113–115 (2020)
Van Schaftingen, J.: Estimates by gap potentials of free homotopy decompositions of critical Sobolev maps. Adv. Nonlinear Anal. 9(1), 1214–1250 (2020). https://doi.org/10.1515/anona-2020-0047
Ziemer, W.P.: Weakly differentiable functions: Sobolev spaces and functions of bounded variation. Graduate Texts in Mathematics, vol. 120. Springer, New York (1989)
Acknowledgements
This work was carried out during two visits of J. Van Schaftingen to Rutgers University. He thanks H. Brezis for the invitation and the Department of Mathematics for its hospitality. P-L. Yung was partially supported by a Future Fellowship FT200100399 from the Australian Research Council. H. Brezis is grateful to C. Sbordone who communicated to him the interesting paper [16] by Greco and Schiattarella which triggered our work.
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Brezis, H., Van Schaftingen, J. & Yung, PL. Going to Lorentz when fractional Sobolev, Gagliardo and Nirenberg estimates fail. Calc. Var. 60, 129 (2021). https://doi.org/10.1007/s00526-021-02001-w
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DOI: https://doi.org/10.1007/s00526-021-02001-w