Function spaces arising from kernel operators

Positivity - Tập 14 - Trang 637-653 - 2010
Guillermo P. Curbera1, Werner J. Ricker2
1Facultad de Matemáticas, Universidad de Sevilla, Sevilla, Spain
2Math.-Geogr. Fakultät, Katholische Universität Eichstätt-Ingolstadt, Eichstätt, Germany

Tóm tắt

Given a probability space (Ω, μ) and a rearrangement invariant space X on [0,1], in certain situations inequalities for spaces of $${\mathbb {R}}$$ -valued functions on Ω are equivalent to the boundedness of an associated operator T K : L ∞ ([0, 1]) → X generated by a kernel K ≥ 0 on the unit square (e.g. Sobolev type inequalities or Riesz potentials on subsets $${\Omega \subset \mathbb {R}^n}$$ ). A natural class of spaces for treating such inequalities is given by $${[T_{K}, X](\Omega) := \{u : \Omega\to \mathbb {R} : T_{K} u^* \in X\}}$$ together with the functional $${u \mapsto ||T_{K} u^*||_X}$$ , where u* is the decreasing rearrangement of u. The investigation of these spaces is our main aim; the nature of the base space X and of K (via its monotonicity/growth properties) play a crucial role.

Tài liệu tham khảo

Bennett C., Sharpley R.: Interpolation of Operators. Academic Press, Boston (1988) Cianchi A.: Symmetrization and second-order Sobolev inequalities. Ann. Math. Pura Appl. 183, 45–77 (2004) Curbera G.P.: Volterra convolution operators with values in rearrangement invariant spaces. J. Lond. Math. Soc. 60, 258–268 (1999) Curbera G.P., Ricker W.J.: Optimal domains for kernel operators via interpolation. Math. Nachr. 244, 47–63 (2002) Curbera, G.P., Ricker, W.J.: Optimal domains for the kernel operator associated with Sobolev’s inequality. Stud. Math., 158 131–152 (2003); 170, 217–218 (2005) Curbera G.P., Ricker W.J.: Banach lattices with the Fatou property and optimal domains of kernel operators. Indag. Math. (N. S.) 17, 187–204 (2006) Curbera G.P., Ricker W.J.: Compactness properties of Sobolev imbeddings for rearrangement invariant norms. Trans. Am. Math. Soc. 359, 1471–1484 (2007) Curbera G.P., Ricker W.J.: Can optimal rearrangement invariant Sobolev imbeddings be further extended? Indiana Univ. Math J. 56, 1479–1498 (2007) Edmunds D., Kerman R., Pick L.: Optimal Sobolev imbeddings involving rearrangement—invariant quasinorms. J. Funct. Anal. 170, 307–355 (2000) Grafakos L.: Classical and Modern Fourier Analysis. Pearson/Prentice Hall, Upper Saddle River (2004) Kerman R., Pick L.: Optimal Sobolev imbeddings. Forum Math. 18, 535–570 (2006) Krein S.G., Petunin J.I., Semenov E.M.: Interpolation of Linear Operators. American Mathematical Society, Providence (1982) Lorentz G.G.: On the theory of spaces Λ. Pacific J. Math. 1, 411–429 (1951) Lindenstrauss J., Tzafriri L.: Classical Banach Spaces, vol. 2. Springer, Berlin (1979) Mockenhaupt G., Ricker W.J.: Optimal extension of the Hausdorff–Young inequality. J. Reine Angew. Math. 620, 195–211 (2008) Okada, S., Ricker, W.J., Sánchez Pérez, E.: Optimal domain and integral extension of operators acting in function spaces. In: Operator Theory Advances Applications, vol. 180. Birkhäuser, Basel (2008) Rolewicz S.: Metric Linear Spaces. Reidel, Dordrecht (1985) Zaanen, A.C.: Integration, 2nd edn (revised). North Holland, Amsterdam; Interscience, New York (1967)